# Mathematical algorithm to check new calculate zero vehicle frame ?

• Hello all !

I am coding a program in visual C# to calculate the Frame robot in 3 points in relation to a measured 3D model. Everything is ok BUT I would like to know what is the algorithm to check the deviation of my learned points robot in relation to my new Frame and the delta between the measure ?

Thanks for your help !

## Images

Edited 3 times, last by poupack ().

• ## poupackJul 12th 2021

Changed the title of the thread from “algorithm for checking my new calculate frame in a program” to “Mathematical algorithm to check new calculate frame ?”.
• I'm not sure what you mean, here. Do you have 3 nominal points in the robot's Base frame, and the same 3 points measured on an object?

What do you want to measure? Differences between the points, or the Bases each point set would create? 3DOF or 6DOF?

• Thanks SkyeFire for your interest!

I will better explain my problem:

I have a 6-axis robot and I want to calculate the zero vehicule coordinate Base frame compared to an already measured table (ex: Romer, Laser etc...) in 3 points.

To mesure the frame robot i declared a tool user and a Null Base Frame.

My calculations are OK and I know how to determine my new reference frame (see the screenshot of my first message).

My question is:

How to calculate and check my new zero vehicule coordinate frame calculated on each point learned robot compared to each point of the measured table?

OR

How to attach mathematically my new calculate zero vehicule coordinate frame to compare the measured table points

For exemple:

My calculated zero vehicule coordinate frame in X, Y and Z:

X = 918,19527

Y = -2169,58373

Z = 2872,24142

1rst point Robot with Tool User and Frame 0

X = 1029,720

Y = -807,803

Z = 11,504

1rst point Pin Table measured with metrology

X = 2877,78

Y = -610,03

Z = 1179,96

With my new reference frame calculated I should have about the same table values in X, Y and Z.

What is the algorithm to apply?

I don't know if I am clear in my explanation !

Thanks !!

Edited 7 times, last by poupack ().

• ## poupackJul 13th 2021

Changed the title of the thread from “Mathematical algorithm to check new calculate frame ?” to “Mathematical algorithm to check new calculate zero vehicle frame ?”.
• You may want to post a sketch of the problem. Posting some values without knowing reference or relationship does not work for me either...

2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

3) read 1 and 2

• .... I don't know if I am clear in my explanation. ....

As You can see on the reactions, You are not clear in your explanation.

The screenshot in your first post is nearly useless.

The only idea that I have:

- you have a measurement system (laser, romer...) and measure a vehicle zero coordinate frame

- you have a robot and want to create/measure a base frame / user frame that also corresponds to the vehicle zero frame.

- now you place the table in the workspace of laser/romer/... and robot and then measure tree points on this table with both systems (laser and robot)

- now you search the algorithm to calculate the frame for the robot that corresponds to the vehicle zero.

• Hermann you're right !

The algorithm to calculate the frame for the robot that corresponds to the vehicle zero i have coded and works BUT i want to determine if the Frame vehicle zero robot matches that of the table.

Theoretically I should have the same table values if I go on the Romer measured spheres with the robot.

I don't know how calculate this step !

• I think the best is that I post a sketch as said panic mode !

• The algorithm to calculate the frame for the robot that corresponds to the vehicle zero i have coded and works BUT i want to determine if the Frame vehicle zero robot matches that of the table.

I made some some tests and the result:

in my opion it does not match

My question is simple - what is the robot manufacturer?

for KUKA you actually have two options in order to calculate the base data:

- 3 points calculation (first point origin, second point along x-axis, third point in in xy-plane)

- 4 points calculation ( for every robot point you have a cad point)

• I'll post a sketch tomorrow to better explain my mathematical problem! Thanks MOM and everyone for trying to solve my mystery !

MOM, the code i am doing is for all popular industrial robots with the fisrt option : 3 points calculation.

• Ok, I posted sketches to better explain my calculation goal. I hope that it's clearer !

## Images

• A screenshot with all the values OK but without the calculation of difference between robot values and Romer values....

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