YRC1000/YRC1000micro Weight Gravity Position Measure

Introduction

The YRC1000 and YRC1000micro robot controller has a W. GRAV. POS MEASURE routine that will cycle the robot through a sequence of moves that allow it to estimate the tool Mass, Center of Gravity, and Moment of Inertia.  While prior generation controllers were also able to use the W. GRAV. POS MEASURE routine to estimate the tool Mass and Center of Gravity, the YRC1000 and YRC1000micro is the first generation of controller to include the estimation of the Moment of Inertia.

Details

Select a Tool File from ROBOT -> TOOL.  Then under UTILITY select W. GRAV. POS MEASURE.  If this selection is not available, change to a higher level SECURITY MODE.

Note that the W. GRAV. POS MEASURE routine is not available on all robot models.

Once the W. GRAV. POS MEASURE screen is displayed, enable SERVO power and hold the FWD key to begin the automatic routine.  The manipulator will first move to a start position where the Upper Arm and the B-axis are both horizontal.  If the robot is obstructed from this position by other system equipment it may be possible to rotate the S and/or L-axis to allow the position.

It is possible to use the HIGH SPEED button to increase speeds of the routine when only positional changes are being made between the actual testing program operations.

Once the initial start position has been achieved it is necessary to release and then again hold the FWD key.  The manipulator will now actuate the U, B, and T-axis in turn to estimate Mass and Center of Gravity of the tool.  Once this is completed it is necessary to release and then again hold the FWD key several more times to allow the robot to move to the orientations and run the Moment of Inertia testing program operations.

Once complete it is possible to accept the results into the Tool Data file.

Warnings

The W. GRAV. POS MEASURE data is only valid for supported FLOOR MOUNTED robot models that are rigidly mounted.

The Moment of Inertia values cannot be calculated if there are values for the TCP X, Y, and/or Z offsets.  Instead, ZEROS will be entered into the Moment of Inertia fields which will also overwrite any pre-existing values.  If there are TCP values present it is necessary to write them down and then re-enter those values once the W. GRAV. POS MEASURE values have been accepted.

Example of results from GRAV. W. POS MEASURE when no TCP values were present:

Results for the same tool with TCP values entered before running GRAV. W. POS MEASURE:

All values provided by the GRAV. W. POS MEASURE are ESTIMATES.  The smaller the robot payload and loading the more error is induced.  This is particularly true of the Moment of Inertia values that are usually much larger than actual.  It is preferable to enter ALL values that were calculated using CAD tools.