3 ms·

Automata: engineering for a post-oil world?

16 points by rudenoise 16y ago

icegreentea 16y ago
I imagine as you start scaling the size of machines/automata up, it becomes more efficient to have your crank/windmill/whatever turn an electric generator that then drives an electric motor. Any ideas on where this tip over point is? You lose the artistry though.
- crpatino 16y ago
  I am not sure to understand what you mean by "scaling up size", would you mind to elaborate? On the other hand... >> it becomes more efficient to have your crank/windmill/whatever turn an electric generator that then drives an electric motor. Efficiency is not an absolute property of systems, but it depends on the variable that you are seeking to optimize. If you talk about energy efficiency alone, this is a really bad idea. First you use the crank to turn the chemical energy of the meal you just had into mechanical energy, then you turn this into electric energy by using the generator, then the generator powers a motor to turn that one back to mechanic energy. Every step of the process has a conversion factor < 100%, and besides that, every step of the chain has leeks in it. The longer and more complex the process, the less efficient. Period. Now, if you need a steady source of mechanic energy, but you have just a sporadic one, this begins to make sense. You connect your sporadic crank/windmill/whatever to a generator, the generator to a battery, and feed the motor from the battery... and you get a small steady flow out of a big but unreliable one. But it all depends of what you are trying to optimize for in the first place.
  - sliverstorm 16y ago
    It also makes sense for routing and weight purposes. You can run electrical wires where no driveshaft can fit.
  - icegreentea 16y ago
    In my (probably overly simplistic view), a generator-motor system will have roughly constant energy efficiency as you make it larger and larger, while the energy efficiency of a purely mechanical system will decrease, as you spend more and more energy on moving the mechanical connections which increases in mass by the cube, while your energy gathering surface goes up by the square. So for example if you had some wind drive automata that plowed a field for you (and assuming constant wind), if you were talking about a machine that worked 1m^2 per minute, a purely mechanical system would have higher energy efficiency. But if you made the design larger so it could work 4m^2 or something, the now you have higher energy efficiency with a generator-motor system.
    - RodgerTheGreat 16y ago
      The notion of wind-powered automata plowing fields immediately brought Theo Jansen's Strandbeest machines to mind- very evocative. Oh, now I need to find some watercolors... or perhaps some plastic tubing.

16 points by rudenoise 16y ago

I imagine as you start scaling the size of machines/automata up, it becomes more efficient to have your crank/windmill/whatever turn an electric generator that then drives an electric motor. Any ideas on where this tip over point is? You lose the artistry though.

crpatino 16y ago
I am not sure to understand what you mean by "scaling up size", would you mind to elaborate? On the other hand... >> it becomes more efficient to have your crank/windmill/whatever turn an electric generator that then drives an electric motor. Efficiency is not an absolute property of systems, but it depends on the variable that you are seeking to optimize. If you talk about energy efficiency alone, this is a really bad idea. First you use the crank to turn the chemical energy of the meal you just had into mechanical energy, then you turn this into electric energy by using the generator, then the generator powers a motor to turn that one back to mechanic energy. Every step of the process has a conversion factor < 100%, and besides that, every step of the chain has leeks in it. The longer and more complex the process, the less efficient. Period. Now, if you need a steady source of mechanic energy, but you have just a sporadic one, this begins to make sense. You connect your sporadic crank/windmill/whatever to a generator, the generator to a battery, and feed the motor from the battery... and you get a small steady flow out of a big but unreliable one. But it all depends of what you are trying to optimize for in the first place.
- sliverstorm 16y ago
  It also makes sense for routing and weight purposes. You can run electrical wires where no driveshaft can fit.
- icegreentea 16y ago
  In my (probably overly simplistic view), a generator-motor system will have roughly constant energy efficiency as you make it larger and larger, while the energy efficiency of a purely mechanical system will decrease, as you spend more and more energy on moving the mechanical connections which increases in mass by the cube, while your energy gathering surface goes up by the square. So for example if you had some wind drive automata that plowed a field for you (and assuming constant wind), if you were talking about a machine that worked 1m^2 per minute, a purely mechanical system would have higher energy efficiency. But if you made the design larger so it could work 4m^2 or something, the now you have higher energy efficiency with a generator-motor system.
  - RodgerTheGreat 16y ago
    The notion of wind-powered automata plowing fields immediately brought Theo Jansen's Strandbeest machines to mind- very evocative. Oh, now I need to find some watercolors... or perhaps some plastic tubing.