Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What kind of engine would you use for this project

  1. Jun 23, 2012 #1
    Hi I'm currently working on a logistic robot for my final project in Mechanical Engineering. My vision is to design something similar in features to this robot:
    http://www.its-eng.com/logistic-robot [Broken]
    I would really like to join military vehicle manufacturers industry so its really important as my final project. The vehicle should drive in any terrain and the engine should be powerful but not too heavy cause I want the soldiers on the force moving with it to be able to lift it when needed.
    Your advices would be highly appreciated!
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Jun 25, 2012 #2


    User Avatar
    Science Advisor
    Gold Member

    A lot more important than your engine choice is what kind of chassis and drive system are you planning on implementing which will "drive in any terrain"? There are a lot of terrains out there, and that will be the primary hurdle. Should it be able to drive up stairs? In 2 ft. dia. rubble? 3 ft. deep snow?

    The engine is easy in comparison because your obvious answer is probably a small 4-stroke gas engine, unless noise is an issue in which case you'll need to go with an electric system with batteries.
  4. Jun 25, 2012 #3
    I vote for a fuel cell powered electric motor. Although I'm bias, but the military has been putting a lot of money into them lately.
  5. Jun 25, 2012 #4


    User Avatar
    Gold Member

    Go away, Topher; the Mopar rule applies here. When in doubt—HEMI!.
  6. Jun 25, 2012 #5
    You state the conflicting specifications of
    (1) light weight for warfighter lifting
    (2) high power density ("drive in any terrain"), presumably under load up steep inclines. And presumably a long way away from an electrical outlet.

    Hmmmm....gotta go with with either "pocket nuke" or "warp drive".
  7. Jun 28, 2012 #6
    Why get an land rover engine and rebuild it like new? I have built performance engines myself a few times now, and spent 5 years in the army.

    Your either going to make a hybrid... have you the budget? Didn't think so.
    Or get a used land rover engine or something similar and rebuild it for reliably.

    If it needs to be really light consider a high powered bike engine, but they're too noisy for the army. Your biggest problem is matching the drive train to the engine. Absolute nightmare splinning axels.
  8. Jun 28, 2012 #7
    You can think of using ultra capacitors-battery combination to power a DC motor.
  9. Jun 28, 2012 #8
    Wanna know how much your final DoD armor req's are going to weigh?

    No.... you don't. That would eliminate 4-cyls and most other gas engines. If you're looking at fuel, it has to be on the diesel end (Mil combat vechs run on either straight diesel or JP-5 (jet fuel) they don't like the idea of transport costs & logistics on multiple forms of fuel.)

    Hybrid+Armor=Very costly anchor (sorry)

    Looking for innovation? Maybe try diesel/electric generators? I think power:weight will be an issue there too.

    This is an industry I'm familiar with. Trust me when I say there's A LOT of hoops to jump through. If you get a working prototype, shop the design to existing contractors and sell it!
  10. Jul 1, 2012 #9


    User Avatar
    Gold Member

    Your desire to allow the vehicle to be liftable by the troops is a useful constraint.
    The Volkwagen military utility vehicle used in WW2 (later sold in the US as 'The Thing' for the surf rec vehicle crowd) was light enough to be manhandled if it got stuck, about 600kg if memory serves. Note the engine was aircooled and built of magnesium, so light weight was part of the design.
    Also note it had no all wheel drive, so no complex heavy power transmission, just have the soldiers push if needed.
    If you provide for impressive road clearance and big wheels, you also have long suspension and power transmission elements, which add weight and cost.
    You might have a more interesting project if you focused on efficiency, keeping your robot cheap and light, rather than overly capable and expensive.
    You could do worse than to look at other past efforts in this area. The Marines have used simple logistics carriers extensively, basically wheeled platforms. Those might be a useful point of departure.
  11. Jul 6, 2012 #10


    User Avatar
    Gold Member

    Meet the Yamaha Banshee: 400 lbs, 50 hp.

    Respectfully submitted,
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook