DPRG mailing list archives: [DPRG] Tarzan's lessons learned at the DPRG Outdoor Challenge

Sat May 17 18:10:01 CDT 2008

On Sat, 2008-05-17 at 16:30 -0500, Michael C. Menefee wrote:
> In the same vein, I've often wondered if magnetically shielding the
> bottom of the robot (much like shielded speakers) would help with the
> rebar problem.
> 

I've learned not to make "iron-clad" predictions (ahem) but I don't see
this technique working at all.  If I read you right, you'd place a
mu-metal sheet (or a superconducting sheet even better) down low on the
robot, probably above the motor(s) and the idea would be that it would
channel all the flux lines originating from nearby structures while the
magnetometer sails above it all in the undisturbed native earth field.

Ideally, in the extreme, forgetting about motors and stuff for a moment,
this would be like driving a normal robot around on a mu-metal parking
lot.  Any of you physics gurus care to take a try at what would happen?

- Robert

> -----Original Message-----
> From: Randy M. Dumse [mailto:rmd at newmicros.com] 
> Sent: Saturday, May 17, 2008 12:04 PM
> To: 'Robert F. Scheer'; 'dprglist'
> Subject: RE: [DPRG] Tarzan's lessons learned at the DPRG Outdoor
> Challenge
> 
> Robert F. Scheer said: Wednesday, May 14, 2008 11:54 PM
> > Microstrain IMU/Compass - this $1500 sensor has been 
> > surprisingly easy to use, given that it is far from simple 
> > inside and is a serially interfaced device; it has required 
> > almost no fuss except for the hassle of the tall mast.  
> 
> An idea occurs to me. Thinking the main magnetic influences were
> below you in rebar and what not. Imagine a compass on a variable
> hieght mast. Take readings down, middle and up. Do you suppose
> you could calculate the ultimate limit of the field with non
> interference from "plotting" the progressive changes with the
> compass higher and higher in the magnetic field?
> 
> Randy 
> 
> 
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