[Dprglist] another interesting rover approach

[paradug]

David,
     Great inputs! Keep them coming. I am just starting to consider what to do for the next RoboColumbus. 
Regards,
Doug P.

From: David Anderson 
Sent: Monday, December 5, 2016 2:09 PM
To: dprglist at lists.dprg.org 
Subject: Re: [Dprglist] another interesting rover approach

Hi Doug,

Nifty.   

A couple of things you might want to consider.   

The Mars rover-style rocker-boogie is, by design, very slow.   In order for the forward rocker to climb over an obstacle the rover must of necessity first essentially come to a stop as it encounters the object, to force rotation around rocker rather than around the wheel.  This means that the design enforces a very, very slow forward motion.  It cannot maintain constant forward speed while climbing over obstacles, or dealing with rough terrain, curbs, potholes, etc.

If you are looking for a platform to compete with Scott's design or jBot's, you will be hopelessly outgunned as far as time is concerned.  We'll wait all afternoon for you to complete the course.   There are other advantages to the rocker-boogie design, of course.  But speed is not one of them.  Quite the contrary.

The second design you linked to does not have this disadvantage, and can maintain forward speed on uneven terrain.  However it appears that the platform does not scrub the wheels sideways very well, particularly on off-road surfaces.   So while straight line travel will be more efficient than the Mars-rover type platform, steering in an off-road environment will be clumsy at best.   Odometry, if that's one of the things you are interested in, will probably be impossible.  You may remember that the real Mars rover can steer it's fore and aft wheels towards each other, in order to pivot accurately.  But that it a much more complex design than those to which you've linked.  And still very slow.

Just some random thoughts.   We studied these designs pretty exhaustively when were were working on the 6-wheel outdoor rover.  That platform was not developed in a vacuum.   ;>)

cheers
dpa






On 12/05/2016 12:41 PM, paradug wrote:

  Here is another interesting 3D printed rover approach. Again, watch the video.

  http://www.thingiverse.com/thing:1583399

  Regards,
  Doug P.

   

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