ABB FlexPicker

ravi

Hi,
     I have a problem with FlexPicker.
Description of the Problem :
I have two points P1 and P2 with a distance of 700mm between them.I am trying to measure the same distance by moving the flexpicker between the two points by jogging.
I move the Tool point to position P1 and record the position of the toolpoint (x1,y1,z1) in Robot base coordinate system.Similarly I move the Robot tool to second position and obtain (x2,y2,z2).When I measure the distance between the two points using x1,y,1,z1 and x2,y2,z2 with the formula Squareroot((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)+(z1-z2)*(z1-z2))  i am getting a different result.I am getting 708mm instead of 700mm.
I checked the Robot with the help of the  calibration program which checks the revolution counters and its fine.What could  be the possible problems for this?

BR
Ravi

John Wiberg

Hi Ravi,

 

I could see all sort of things that could go wrong here.

First I'm curious how you measured the distance in real life between P1 and P2?

Then you say that you use the "toolpoint", so which tooldata do you use and how accurate was the tooldata when you configured it? How many points did you use when you created the tooldata?

Then comes the question how you have calibrated the robot, which method was used? Does it have Absolute Accuracy option? Has it been serviced and recalibrated since it left the factory etc. Which FlexPicker is it? Has it been in a collision since last calibration, etc?

What I would do is a reverse test as well. Do a linear jog between as far a point on positive X to negative X, see how many mm the jog window says and measure it in real life, then do the same for Y and Z. Maybe place a workobject and jog in the workobject so that I can go from one extreme to another.

ravi

Hi John,

        Distance measured by a standard scale(ruler).I created a new tooldata.The  tool was measured with an accuracy of 0.1mm.I had defined the tool based on the procedure given from ABB.Page no 154and 155 of the manualOperating Manual IRC5 with FlexPendant,M2004Document ID: 3HAC16590-1Revision: J.
Robot calibration is done by updating the revolution counters.Axis by axis moving each axis to its calibrationg point and updating it.The robot used here doesnt have absolute accuracy.
FlexPicker used  is IRB360.Regarding the collision I am not sure about it....I have been using this recently.I will do some trials by jogging the robot in its X and Y axis and let you know about the results.

vulpes_h

Check the calibration offset together white the calibration tool to see if the fine calibration is wrong.
and it makeA's the revolutionconters corect.