difference between Euler angles and roll pitch yaw angles

[Priyadarshini Ravichandran]

Hello all,

 I would like to know the difference between the euler(tr2eul) and roll pitch yaw angles(tr2rpy), by definition it appears to be same, please let me know there are different representations of orientaion matrix like quaternion, axis angle. Thank you.

[Erik van Oene]

Hi,

It is just an other way / sequence or successive rotation to fully describe an orientation.
Just google or take an average robotics book. It is explained everywhere.

Erik


Op donderdag 15 juni 2017 17:15:52 UTC+2 schreef Priyadarshini Ravichandran:

[Priyadarshini Ravichandran]

Yes sir, I got that answer its just intrinsic and extrinsic rotation. I have another doubt...To validate my inverse kinematics algorithm for desired transformation matrix(orientation and position) i got joint angles(as an output), just to cross check I gave those joint angles to fkine command... I got the same position values but orientation matrix is different, please let me know...why I am getting like that.....

[Erik van Oene]

Do you have a 6 DOF system (or more). If not, the orientation may nog be fully controllable.

Please send the code such that we can investigate it further.

Erik

Op vrijdag 16 juni 2017 21:16:37 UTC+2 schreef Priyadarshini Ravichandran:

[Priyadarshini Ravichandran]

Dear Sir, 

I have 15 DOFs in total and I have attached the code.....

[Erik van Oene]

Hi,

I have no access to Matlab at the moment. However, I will check this out if I do.

Erik

Op maandag 19 juni 2017 09:50:33 UTC+2 schreef Priyadarshini Ravichandran:

[Priyadarshini Ravichandran]

Hi, yeah sure sir..thank you so much

[Erik van Oene]

Hi,

So thats quite some lines in the script... I'm guessing that the variables: 'el'  and 'er') contain the error signals. 

I changed the script a bit such that I can plot the error over time (the loop). My results look fine to me, however, at the start both position and orientation is a bit off. You see the robot arms jump a bit in the first few loops, but after that both arms follow the trajectory.

In the loop I keep track of er and el to plot them afterwards. Results can be found in the attachment. If you the same results, than please point out which values you don't trust. If your results are different, than you probably run a older version of the toolbox, have some shadow function.

I ran Toolbox version 9.10 on Matlab R2017a

Erik 

Op vrijdag 23 juni 2017 13:18:30 UTC+2 schreef Priyadarshini Ravichandran:

[Peter Corke]

I am not sure what it means "by definition it appears to be the same".  They involve sequences of rotations about different axes.