Touch Sensing While Rotating External Axes

A new macro job (TOUCH-R*S*) was created to allow for the following:

1. Touch sensing / AccuFast searching while rotating an External Axis
2. Creation of a rotation shift amount for the External Axis

Programming:

Deploy the TOUCH-R*S* macro job into the robot/external axis job.  For example, if using an R1 and S3 positioner, the parent job should be an R1+S3:S3 formatted job.  You then would program in the macro job TOUCH-R1S3 as follows:

There are three arguments that must be programmed inside the macro instruction’s Argument Setting screen:

• ROBOT POSITION = location of welding torch (if using Touch Sensing) or AccuFast sensor during search motion.  Only the external axis is moved during search motion.  The robot does not move.
• EX AXIS-START = starting location for search motion.  The sensor should be OFF (i.e. wire should not be touching the surface of the part).
• EX AXIS-MASTER = (1) During initial teaching, start with the location of the EX AXIS-START position, then jog the External Axis in the direction you’d like to use while searching.  You only need to jog the External Axis a few pulse counts for this step. Now, teach the EX AXIS-MASTER location as this position to which you just jogged.  (2) Next, when you run AutoTeach, the External Axis is automatically moved to the point where the sensor turns on, and you’ll be directed to Re-Teach this Argument to the new location of the External Axis … the Master Part location.

You’ll need to set the degree of External Axis movement used to search for the location of the part.  SEARCH DIST(DEG) is specified in degrees. Typically 5 or 10 degrees is used, but larger values can be specified.

Note, after successful execution of the TOUCH-R1S3 macro job, the rotation shift amount is placed into an EX variable.  This shift amount can then be deployed using SFTON EX###.

Example:

After AutoTeach is successfully run and the accurate location of EX AXIS-MASTER was re-taught, during routines playback the robot moves to EX AXIS-START location

and then begins searching towards the surface of the part by rotating the External Axis.  Eventually the sensor contacts the part and the External Axis motion stops.

The user deploys the SFTON EX### instruction and the welding torch is in the weld seam.

Next, a deviated part is placed into the external axis. The TOUCH-R*S* macro job is re-run and a new External Axis shift amount is calculated. The SFTON EX### is executed again and the welding torch is again in the weld seam.  Note:  the robot position is never shifted in this example; instead, the external axis position is shifted to move the weld seam to the welding torch.

Requirements:

• Touch sensing or AccuFast sensor
• “Station Angle Display” function MUST be enabled
• Coordinated motion must be enabled and the R*+S*:S* group combination must be defined.