Program Example 8.3

Example Type:
Using Don’t Care Pixels for the Part Blob Search Window

Configuration

• Number of Robots: 1
• Number of Feeders: 1
• Number of Parts Types on the Feeder: 1
• Number of Placement Positions: 1
• Camera Orientation: Fixed Downward Camera over Feeder#1

Description
Even with the backlight turned on, the corners of the tray can have shadows. If the Part Blob search window includes the corners and if the Blob’s thresholds are not properly adjusted, then the shadows can be mistakenly identified as parts. The Part Blob Sequence is used to detect individual parts or an accumulation of parts. If the Part Blob sees the shadows as parts, then the system will make a bad decision on how to vibrate.

The following is an example of how the corner shadowing can be misidentified as parts.

The Blob’s Search Window can be masked by painting "Don’t Care Pixels" in the regions where you do not want to search (i.e., the corners of the tray).
Right click on the Blob and select "Edit Window" from the fly out menu or select the SearchWin "EditWindow" property for the Blob.

Use the paint brush to remove the tray from the Search Window.

Now when you Run the Blob, the tray will not be included in the Search Window (as shown below).

No special part feeding code is required.

Sample Code
Main.prg

Function main
    If Motor = Off Then
        Motor On
    EndIf
    Power Low
    Jump Park
    PF_Start 1
Fend

PartFeeding.prg

Function PF_Robot(PartID As Integer) As Integer
    Do While PF_QueLen(PartID) > 0
        P0 = PF_QueGet(PartID)
        Jump P0
        On Gripper; Wait 0.2
        Jump Place
        Off Gripper; Wait 0.2
        PF_QueRemove PartID
        If PF_IsStopRequested(PartID) = True Then
            Exit Do
        EndIf
    Loop
    PF_Robot = PF_CALLBACK_SUCCESS

Fend