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Author Topic: Advantages and disadvantages of common steering methods  (Read 4923 times)

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Offline JoeTopic starter

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Advantages and disadvantages of common steering methods
« on: April 08, 2007, 04:29:58 PM »
I have always gone with the single differential steering and casters. Now, however, I'm dealing with a surface that is flat but bumpy. I've been looking at a lot of steering methods online and find that there are basically 2 different approaches for all terrain robots.

  • Dual differential
  • Tank treads
  • "Car Style"

I'm sure their are advantages and disadvantages to each. Mainly, What is the purpose of having 2 motors on each side (dual differential) and what's the deal with tank treads in general? My guess is they give you the simplicity of single differential with greater traction, etc. I've searched the Internet over for a side-by-side comparison of the 2 but found nothing. This board could be the 1st place to clear this up.

Also, has anyone ever constructed anything with the Lynxmotion tank tread products (http://www.lynxmotion.com/Category.aspx?CategoryID=94)? They look pretty tight but kinda pricey considering how quick they would add up for enough parts to actually build something.

Offline Somchaya

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Re: Advantages and disadvantages of common steering methods
« Reply #1 on: April 08, 2007, 04:47:47 PM »
2 motors on each side for a dual-differential, as you name it, is probably so that there's more torque than just one motor. Using 4 wheels over 2 driven and a caster is more for stability than anything else I think..

Tank treads are useful when the terrain you're traveling on is bumpy, or not totally solid, like sand and gravel. The treads give extra traction and helps reduce the chance that the robot is stuck on a bump and the wheels don't contact the ground, which can happen with wheeled robots..

I guess when you compare tank treads vs dual differential, the first difference I can think of is that treads are very difficult to build, vs wheels which are more easily attached. Tank treads also make the robot a lot harder to turn, because of the extra traction. A regular differential (2 wheels and a caster) is the easiest to turn, followed by the dual-differential, then tank treads.
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Offline Admin

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Re: Advantages and disadvantages of common steering methods
« Reply #2 on: April 17, 2007, 07:10:15 PM »
FYI, tank treads are also differential :P

another steering method is 4 wheel steering:
http://www.societyofrobots.com/robot_taurus2.shtml

its the same method as used by the mars rovers . . .

the difference between them, not covering the mechanical differences, is the holonomics of each. the algorithms required for each of the 3 steering methods is very different:
http://www.societyofrobots.com/robot_omni_wheel.shtml#holonomics

 


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