Calibration of the robot-cell
In order to compensate for the errors coming from the actual robot and part fixture location, calibration of the robot-cell allows determining the relation between the car frame and the robot frame. This calibration is required for the robot programs downloaded from simulation.
For this operation, we require the use of the DynaCal system from Dynalog because of its accuracy, its speed, and its adaptability in spot-weld installations. The measurement basis of this system, which comes under the form of a small unit, is a precision cable connected to a high- resolution optical encoder. In the case of a standard spot-weld application, the calibration procedure consists of consecutively locating the unit to a minimum of 3 locating pins on the fixture and of connecting the other side of the cable through an adaptor to the spot-weld gun’s TCP. For each locating pin, several robot positions are generated, and the corresponding cable measurements are used by a PC-based software to calculate both the fixture frame and the TCP frame. We invite those integrators or their subcontractors who do not own or know this system yet to contact Dynalog in order to learn more about this calibration procedure.
The classical method of using the robot to teach some points on the fixture to define the alignment is no longer accepted.