To my knowledge there isn't a full-active 'upper berth' marketed for a sleeper cab, and you would need considerable stiff, and consequently heavy, structure up high in the sleeper cab itself to allow it.
It could probably not adapt the mechanism of the Bostrom seat effectively, either.
I have the impression that most driver teams would only require a 'lower' for typical road-speed running, and might not want to spend for full-active motion and noise cancellation in the typical sleeper-bunk location relatively well between the axles.
Simple passive isolation probably gives a 'good enough night's sleep' after having driven a full shift...
OvermodI tinkered for years trying to design a method of multiaxis ride control that would work on an upper berth
How do they work on OTR Trucker sleeper cabs? Is it the whole cab, just the sleeping part or none of the above? Just curious.
The problem applying it to beds is the nature of the actuation.
The basic principle is the same as for guidance with an inertial platform: the part of the 'bed' carrying the mattress has to be free to 'float' in any direction (including tilt) and be given sufficiently powerful and quick actuators to keep it 'stably positioned' regardless of what the car and suspension are doing under and around it.
In practice there are response times for different levels of control, remembering that there are forces necessary to round curves and negotiate grades that may confuse excessively simplistic servo systems.
A much more significant condition is that the whole duration of operation of the bed will be during sleep or resting, where even comparatively quiet whines, whooshes, or other mechanical noises will rapidly become the equivalent of water torture -- isn't typical plastic 'giggling' bad enough already? You notice this noise less when it's under a seat in a noisy bus which is playing Muzak, or when you're distracted with some foreground-consciousness activity.
I tinkered for years trying to design a method of multiaxis ride control that would work on an upper berth. They were all relatively big, heavy, noisy and susceptible to failure or safety concern.
We did get as far as injecting gray noise with a predictive noise-cancelling component through the equivalent of a pillow speaker, and it is now cheap to provide a programmable 'ambient sound' generator (with the range of typical sleep sounds including carefully mastered and filtered railroad-track sounds!) at each berth to assist with this.
Would not the most important, effective, useful use of this technology by Amtrak and VIA be for sleeping-car beds?
GrampWonder how the hover seat compares to a Volvo or other luxury car seat that is truly comfortable?
I doubt the bus seats take full advantage of this. You could quite easily adapt a good automobile seat with up to 18 adjustment motors (and put an app on your phone to run the seat to your 'saved' preference in seconds, then change it for lunch, and then after dinner, with similar ease and quickness...)
While we are on the subject of those 18 adjustments and thinking about Gramp's point about tired old upholstery: at least some of those adjustments can be air bladders, like the ones that are still going strong in my CLK55AMG nearly 20 long, hard years ago. Those might compensate for tired, compressed padding (as in almost every other Mercedes seat 2 decades old!) with periodic simple adjustment not requiring deadheading to and from Beech Grove...
Note that the hoverseat mechanism would work just as effectively for a 2x seat as it does for a parlor-style single armchair. Which leads me to speculate if there is a decent cost-effective way to 'hover' the articulated leg rest of something like a Sleepy Hollow seat when extended.
(Incidentally, in the just-for-grins department, my version of 'advanced passenger train' from the early '70s (the one that has its own classified ad in Trains) featured active hydraulics in the secondary suspension that gave 'hover' ride to each end of each car. The problem with that was dealing with the noise it made... we have better electric actuators now.
The last Amtrak Superliner I was on had a seat that had been sat on too many times. Became uncomfortable pretty fast. Wonder how the hover seat compares to a Volvo or other luxury car seat that is truly comfortable?
My understanding was that Nystrom himself noted that 'his' trucks when optimized for high speed rode harder at lower speed, including the sharp lateral involved in crossovers. It would take a different approach to truck design to get out of this issue, and some of the 'wisdom' that ensued (the stiff primary/soft secondary and air secondary) turned out not right either.
The primitive predecessor of the hover-seat is the Bostrom air-ride (which made modern high-speed OTR trucking practical). The new version provides many of the advantages of inertial gyro guidance both laterally and vertically; it might be easier to provide a rail version as there is less tendency for longitudinal shock or surge to reach 'unpleasant' levels.
I might be tempted to see if the seats could be given a little bit of negative cant deficiency for seated passenger height to simulate tilt on curves. That might require only one additional motor or actuator, but the curved lateral tracks might need to extend beneath floor height...
OvermodYes, this is something that could, and should, be tried in rail travel. Retuning the mechanism to a soft-secondary railroad suspension should not be difficult, and predictive actuation in a train promises a smooth ride even over highly 'uncertain' track.
Wasn't the former Milwaukee Road Nystrom truck known for being a smoother ride through rail crossovers than the trucks in use today because of their additional shock absorbing? I read that somewhere but never heard much about comparisons between Nystrom and other trucks.
EnzoampsJust curious, are people not taking Amtrak because of the seats?
Heh, it's not the seats, it is the ride IN the seats. Yes they do complain about rough track on some routes if you read Amtrak passenger comments.
Just curious, are people not taking Amtrak because of the seats? I've always been comfortable. I like the seat spacing, in that the fellow in front of me can lay back all the way without putting his head in my lap.
I never worried much about wavy track when sitting. It is when walking down the aisle that I fear being thrown into someone's lap.
Yes, this is something that could, and should, be tried in rail travel. Retuning the mechanism to a soft-secondary railroad suspension should not be difficult, and predictive actuation in a train promises a smooth ride even over highly 'uncertain' track.
I would make them larger, though, which the greater width of a PRIIA-compliant shell would permit, and I'd make it possible to have either a large or small 'tray table'. I am too old-fashioned not to see the desirability of good 'in-flight entertainment' even if it's only a rebranded version of hospital TV... and closer seat tracking that still supports the long reclining angle eould facilitate the necessary big 'seatback' screens...
Seems like whomever is running this bus line has found a seat that smoothens the ride more. Perhaps Amtrak could experiment a little with these type of seats in first class or long distance coach???
https://www.youtube.com/watch?v=Oh1ULPYMQhI
I'd say also try them in a Locomotive Cab but not sure they would be maintained well there.
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