Tips for Conveyor Calibration
Workpiece and Tool
In order to realize precise pickups, it is necessary to perform a correct teaching in the conveyor calibration. To move the center of the end effector to the feature point (e.g. the center point) of the workpiece detected by the camera, it is recommended, for example, to use a workpiece and a tool as described below.
workpiece : Teaching point (a) is easy to be found
Tool : Tip point (b) is easy to be found (Make sure to configure the tool settings.)
Example of the workpiece and the tool used in the conveyor calibration
KEY POINTS
Perform a model teaching by overlaying the model origin of the Corr or Geom object on the teaching point, and adjust the positions of the camera coordinate system and the conveyor coordinate system correctly. If the teaching point is the center of balance of the workpiece (a perfect circle or a square), the center can be detected as the model origin by the Blob object.
Z Value Adjustment
The workpiece and the tool used in the conveyor calibration can have a different height from those used in actual workpiece handling. By adjusting the Z value after replacing the tool and the workpiece, errors related to the Z offset can be solved.
In the following cases, Z value adjustment is effective.
- Tool cannot reach and pick up the workpiece. (Z offset is too large)
- Robot collides with the workpiece and damages it. (Z offset is too small)
Like the above cases, redoing of the whole conveyor calibration process may not be required. If there is a problem in the pickup height, adjust the Z value as a first step.