ABB robotic quaternion euler calculation

[amaurythomas]

Hello,

I am developing my own abb invert kinematic robotic plugin for a specific project.
However I need understand all the calculation to feed the rapid code.
Someone can quickly explain how to calculate the number needed (Please have a look to the red rectangle on the image below) acording to the oriented planes.

Best,

Amaury

[visose (Vicente Soler)]

They are quaternions (euler would be 3 numbers). You can check my robots plugin: http://www.github.com/visose/robots

[Joseph_Oster]

I just recently heard about “Quaternion Rotation” from @Michael_Pryor - sounds fascinating:

Frames along curve but with the first and last frames set to a certain angle

Yes, with Pufferfish. Use the Tween Two Curves On Curve component. Mainly because it has Quaternion Rotation which you will need for this interpolation of planes. It uses Quaternions from Rhinocommon. [Capture] TweenTwoPlanesOnCurve.gh (6.8 KB)

More here:

Code examples using quaternion for rotation?

I have to look into quaternions. But can anyone provide with a code example of how to use them? For example rotating an object around a vector, and transforming an object from one plane to another. I know there are plugins that can handle quaternions (Falcon and Pufferfish has it) but I need to be able to code it myself (RhinoCommon quaternions). I tried a bit but the results doesn’t make sense to me… What I did was creating a vector from two box corners (see fig below) and created a transfor…

[visose (Vicente Soler)]

If you just want to convert planes to quaternions, this is the code I use:

public static double[] PlaneToQuaternion(Plane plane)
{
var q = Quaternion.Rotation(Plane.WorldXY, plane);
return new double[] { plane.OriginX, plane.OriginY, plane.OriginZ, q.A, q.B, q.C, q.D };
}

Or you want to interpolate 3d rotations? That’s more tricky and theres no “best” way, but a usual way is using axis angle, this is the code I use:

public Plane CartesianLerp(Plane a, Plane b, double t, double min, double max)
{
t = (t - min) / (max - min);
if (double.IsNaN(t)) t = 0;
var newOrigin = a.Origin * (1 - t) + b.Origin * t;
Quaternion q = Quaternion.Rotation(a, b);
q.GetRotation(out var angle, out var axis);
angle = (angle > PI) ? angle - 2 * PI : angle;
a.Rotate(t * angle, axis, a.Origin);
a.Origin = newOrigin;
return a;
}

[Michael_Pryor (ekim)]

Hi Vicente, have you seen these ones from Daniel?

Code examples using quaternion for rotation?

Hi Rolf, A little late to this quaternion party, I’m not sure why you say you have to use quaternions, but not what you want to do with them - it seems a strange way round to start to me They do certainly have their uses, but depending on the problem may not be the only or best solution. Anyway, assuming this is something to do with rotation, to throw another example into the mix, I’ve included below a simple linear interpolation, and also something I did using Quaternions to inte…

[visose (Vicente Soler)]

Not that one, but an older one, which I reference in the github repository:

    /// <summary>
    /// Quaternion interpolation based on: http://www.grasshopper3d.com/group/lobster/forum/topics/lobster-reloaded
    /// </summary>

Slight advantage of my code is a bit less newing and follows c sharp conventions rather than Daniel’s weird pascal case on parameters and local variables

[Michael_Pryor (ekim)]

then I am sure you will love his QuaternionSpline.gh Obfuscation

[amaurythomas]

thanks a lot for your help, I will look at this carefully !!!

[visose (Vicente Soler)]

Very creative. I was learning a bit of JavaScript recently and my first thought was that I opened the minified version.

[RIL (Rolf)]

@Michael_Pryor

QuaternionSpline.gh

Here’s a very special application where quaternions can help - Avoid Gimbal Lock or you are going to Burn! (you are still going to get smoked, but anyway)

https://twitter.com/VergaraLautaro/status/977215144509034497

// Rolf

[amaurythomas]

Thanks a lot, I had time to have a look to your code, it was very helpful !!! now I need to create the socket the send the rapid code !!!