Hybrid-Electric Roadtrains by 2020

Safer, Quieter, Cleaner and More Sustainable Land Transportation

What if something happens to the lead driver of a road-train? Would everyone connected be screwed? It is scary to rely on a complete stranger to not fall asleep or have a heart attack or swerve to avoid a deer or spill hot coffee on his/her lap. Would that put everyone in the train in danger? With a real train there are tracks and a crew of more than one to handle an emergency. If you have 6 cars following each other and mimicking the first car’s moves, there could be a 6 car crash.

Is that what guide rails would be for?

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Comment by Bob Phillips on January 31, 2010 at 10:38am
I'm a bit non-plussed by your showing up here incognito. It's cool that you are interested in this technology, but I'd like to know more about you.

As for the concern about problems in the lead vehicle; you have identified a failure mode that has to be considered in the engineering design of the system. There is a formal process for doing this called FMECA, for Failure Mode Effects Criticality Analysis.

The Federal Motor Vehicle Safety Standards (FMVSS) establishes failure mode analysis in (perhaps too much) detail for critical subsystems. Toyota recently got bit with their throttle control. The FMVSS calls for a number of tests to see what would happen if, say a throttle position sensor failed. Missing from the analysis was a failure of the pedal itself --which, at this time, appears to be the real problem.

What seems to have been missing from the Toyota FMECA is the sort of insight you offer here: "What if?"

So, we have the challenge of looking at dead lead driver in an eRT, the Failure Mode
The Effect: BANG, 6 vehicles full of people and goods are at risk.
The Criticality: Something has to be done

and now the fun begins --how can we save the train?

For the virtually linked mode (under intense study in Japan under NEDO sponsorship), all of the cars will have speed, headway, and path control; so the solution might be to simply stop the lead car when the system recognizes that the driver is snoozing. Then, the collision avoidance and lane keeping systems in the following cars will "save" them. Action to take: Specify, design, implement, test a driver failure recognition system. There is a lot of precedent work in this area. Much is focused on inattentive drivers, and the Snooze Alarm to be implemented here would be based upon a much more easily recognizable driver failure. SLAM DUNK to fix

In the case of the physically coupled eRT implementation, we have a different problem entirely, and only the rudiments of a solution to "Dead Lead Driver" are in place.

Firstly, we are barely started in our effort to assure that the following cars can accurately and stably follow the leader. We think that it will take more than a series of trailer hitches to make the train work, and that it may be necessary to provide communication links between the cars that would command controllers in each vehicle to participate in steering, powering and stopping the combination of vehicles.

Your failure mode might be addressed by making the intra-vehicle communications "run both ways," so that some automata applies to the lead car, too. Thus, we come to the possibility that the combination of vehicles might be required to steer and stop the leader.

Thank you for your contribution to our FMECA thinking.



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