CNC Lathe Machine Tending 3.1

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Application Video

Scenario

  • Pick a part from one of two possible rows in a presentation fixture.
    • The second row contains extra parts in case the first row becomes empty.
    • If the first row contains parts, always pick from the first row.
  • Wait for the machine door to open (signal sent to robot from machine).
  • Move into the machine.
  • Grasp the finished part and trigger the chuck to release.
  • Move to place the new part, use a force push to ensure the part is correctly seated and trigger the chuck closed.
  • Move to place the finished part and trigger the machine to start.
  • Place the finished part to allow a human operator to perform final inspection.
  • Repeat the process continuously.

Gripper Information

Notes:

  • End of arm tooling is a customer dual pneumatic gripper that was designed and built by a 3rd party. The PSG was not available when this application was created but would be a good option for similar tasks.
  • Center of mass and tool center point details were obtained using SolidWorks model of EOAT.
  • Two different subtools and tool center points are used to define each gripper endpoint location.
  • When training a pick or place Move To, the associate subtool is selected as the tool center point for the pose.


Gripper Image

3.1 CNC Machine Tending EOAT.PNG


Tool Settings

  • Tool Center Point
    • Subtool 1 = (X)=0mm, (Y)=49mm, (Z)=164mm
    • Subtool 2 = (X)=0mm, (Y)=-49mm, (Z)=164mm
  • Mass = 2107g
  • COM = (X)=0mm, (Y)=0.3mm, (Z)=48.5mm

3.1 CNC Machine Tending Tool Settings.PNG

Task Overview

Note: This task was created using Intera 5.1. Some differences may be seen if you are using newer versions of Intera.


3.1 CNC Machine Tending Task Overview.PNG

Create and Set Up Signals and Variables

Signals

Signal Name Type Line
Pick 2 Ready Input DI_0
Pick 1 Ready Input DI_1
Machine Ready Input DI_2
Start Machine Output DO_1
Open-Close Chuck Output DO_2

All of the signals are configured with a default value of 0 (or false). The image below shows the configuration of one of the signals.

3.1 CNC Machine Tending Signal.PNG

Variables

No custom variables used in the task.

Key Task Elements

Task Work Flow

3.1 CNC Machine Tending Task Workflow.PNG


Initialize

Notes:

  • The robot moves to a home position and then sets the valves in the controller to the proper configuration to ensure both grippers are open.
  • The robot moves to and re-registers all landmarks.

3.1 CNC Machine Tending Initialize.PNG


Pick from Tray

Notes:

  • Before picking, a Wait Until node is used to ensure parts are present at one of the two pick locations using input signals.
  • When picking, the first row is the priority. If this row has available parts, the robot will pick from the first location every time.
    • If no parts are available in the first row, the robot will pick from location 2.
    • This logic is controlled using a Priority node with two Do If nodes.

3.1 CNC Machine Tending Pick From Tray.PNG


Move to Machine and Wait

Notes:

  • Wait Until node is used to prevent the robot from entering the machine until an input signal is received from the machine.
  • A delay is required after the Wait Until node in order to allow time for the door to open as the signal is sent when the process is complete, not when the door is open.
    • The length of this delay was adjusted to decrease cycle time once the application was running successfully.

3.1 CNC Machine Tending Move to Machine.PNG


Pick Finished Part

Notes:

  • No miss pick logic is used in the application. If a miss pick occurs, the robot will continue running without stopping or displaying an error.
  • Before moving to the retract point, an output signal must be sent to open the chuck holding the part.

3.1 CNC Machine Tending Pick Chuck.PNG

Place New Part

Notes:

  • Apply Force is used in the Contact Move to ensure the part is flat against the back of the chuck before triggering the chuck to close.
  • While still in the Contact Mode, a short delay is applied to give the robot time to start applying the force and then a signal is sent to close the chuck. Another delay is used after the signal is sent to ensure the chuck closes fully before the force is no longer applied.
  • Standard Move To nodes are used before an after the force is applied to ensure the robot is stable at the beginning and end of the force push. This is a best practice when using apply force.

3.1 CNC Machine Tending Place Chuck.PNG


Trigger Machine While Exiting

Notes:

  • A series of four Joint moves are used for to exit the machine.
  • The Start Machine signal is sent while the robot is exiting the machine in order to optimize cycle time.
    • This is done by placing a Set To node in the middle of the series of joint moves.
    • A series of joint moves are treated as a path during motion planning and a Set To node will not break up or pause this motion. This allows for the signal to be sent while the robot is moving without pausing or slowing the robot motion in any way.

3.1 CNC Machine Tending Exit Machine.PNG


Place Finished Part

3.1 CNC Machine Tending Final Place.PNG

Task File Download

Note: This task was created using software version 5.1.2.4.

Example CNC Lathe Machine Tending