I can’t access the sample LabView file either, it appears as though the document doesn’t exist anymore. @Ether, would you be able to re-upload the document that was supposed to be at the following link?
All set now. I was trying to get to Ethers “4 wheel independent drive & independent steering (“swerve”)” paper and could not initially get to any of the related PDFs (and other files). If I run into another I’ll raise my hand again. Thanks!
If you know what the desired steering angle is, you can tune the PID yourself to get your desired steering velocity. Also make sure you allow it to wrap around at 360 degrees. I think PIDController can help with this.
Hi you all,
I found this topic and all the information, PDF and excel tool are great! I´ve just have a question… I´ve spend some time but I was not able to find out why (wr)x=wL/2 and (wr)y=-wW/2 in PDF page 4. Can anyone help me? Like step by step calculation to get those expressions… I would really appreciate it
first some geometry:
rotational velocity is perpendicular to the radius so D=90-c
a=C angles between parallel lines so D=90-a
looking only at WR and its components:
we can use trig to find the absolute values of X and Y
sin(D) =Y/WR multiple both sides by WR
sin(D) * WR= Y
sin(D) is also sin(90-a) (remember D=90-a
sin(90-a) = cos(a) trig identity
so we get:
cos(a)*R *W =Y
from trig we know that: cos(a)=(w/2)/r
after multiplying both sides by r: cos(a)*r= w/2
therefore the absolute value of Y equals w/2 * W
sense it is the absolute value you maybe need to negate if it is in the opposite direction from the positive direction of your axis (such as in the case for the x component in this example)
the math is the same for the x component but replace of the sin with cos and vise verse