How to create a self robot Calibration Program

[alfamoto]

Is it possible to create a robot calibration program for its own? Let say I have a physical tool center point, machined, that is perfect, is set besides the robot, I position the robot over the tip pointer and record its position values,S L U R B T and save them into a variable, I want the robot to call up to run this program call (center point) to check the robot accuracy after running many jobs. For example, the robot goes to the pointer and the position values are not accurate as they should be when (center point) program was created for the first time in the program, let say L axis is 500.00 the first time the robot was taught, from the tool center point and now the L axis shows 510.00. Now is 10.00 degrees off at axis L, how to make the robot to reset itself and to self move back to the pointer, smart guys, tell me this is possible to create. And if is possible send me a job example, my robot is a SK6 with a MRC controller VERSION: 3.900A(E)-00
PARAMETER: 2.11
Thank you.

[Robo Guru]

Ok, well I've seen this done but unfortunately not with an MRC.

NX/DX and possibly XRC have commands that let you read and write ABS values.  (WABS, RABS)

Motoman developed a product that really in my opinion was only beta.  They called it tool sight 6D.  In a nutshell, you essentially brought your robot to a known position and measured the deviated via laser sensors.  A PC program was also required because you have to calculate the inverse kinematics of every joint.

Like I said though, this was some beta stuff that never really reached maturity.

Rg

[Fabian Munoz]

Interesting question alfamoto
I'm going through the same issue with another robot manufacture

Back to your numbers

Which device is 10 mm off ?  Is it the pointer ?, the robot ? or both ?

1) Pointer off ?  I'm assumiing the pointer is attached firmly not easy to bend etc
2) Robot off ?  Time to do some maintenance

Robo Guru explained the tool sight, the other thing i can think of is a vision camera (Obviously I dont care about money, LOL).
BTW, I didnt know about WABS and RABS,
So, in general I dont know (or they dont exist) commands to "calibrate" the robot by itself, I think you end up modify a USER frame and that will be the easiest way

[Robodoc]

Alfamoto,

What you describe is how the Motoeye works.  In stead of a machined point, Motoeye uses two fiber optic sensors set at right angles.  The robot searches in one direction to brake the beam and records the position, it then searches in the opposite direction to the same beam and subtracts the difference to find the center of the beam.  It does this same pattern to the second beam to find it's center.  If this pattern is done once a cell is set up, any difference in the search pastern is how much the tool, or robot  has moved.  You can then shift your programs the offset.

[zdrav]

MOTO TAC - it`s selfcalibration tool and program. It was made  in Swedish Motoman,uses search function .If You are interested I will send more information

[alfamoto]

Thank you guys, and zdrav, please send me the moto tac info, at least I can ready and probably learn some of it.

[zdrav]

It`s  the all I have