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DH_Extractor

Posted: 25 Jun 2018, 01:25
by algontijo
Hi.

Anyone knows why DH_Extractor doesn't work with MTB_Robot?
It also doesn't work with robots that I've been making.
It seems the only problem is the parameter d.
The other parameters seems right to me.

Please help me.

Thanks

Re: DH_Extractor

Posted: 27 Jun 2018, 10:02
by coppelia
Hello,

not sure what you mean... what is d supposed to be in the MTB robot?

Cheers

Re: DH_Extractor

Posted: 27 Jun 2018, 13:26
by algontijo
Hi.

The problem is in d parameter of DH Extractor.

"Between 'MTB_axis3' and 'MTB_axis4':
d=0.0000 <<--Here i think there should be a value diferent from zero
theta=0.0
a=0.0000
alpha=0.0"

In every other robot that i create this d parameter is also zero for any possible configuration.
In the list of models of non-mobile robots the only robot that the d parameter is also zero is the MTB robot,
That's why i think it's a similia situation i'm trying to understand.
There are any limitation on the DH Extractor program ?

Thanks for the reply. But i still need help.

Re: DH_Extractor

Posted: 28 Jun 2018, 13:34
by coppelia
As far as I can tell, all axes are parallel in the MTB robot. The two last axes, MTB_axis3 and MTB_axis4 are even coincident. From Wikipedia:
d: offset along previous z to the common normal
With parallel axes there is not one common normal, but an infinite amount of common normals. With coincident axes that normal does not even exist.

Cheers