Create Place Moves

The gripper moves through three poses in order to place the box: Approach, place and retreat. In this exercise, we will create these place poses for the TCP coordinate frame.

Locate Function

• In the main program , locate the function call to application.computePlaceToolPoses().

• Go to the source file of that function by clicking in any part of the function and pressing F2 in QtCreator.

• Remove the first line containing the following RCLCPP_ERROR_STREAM ... so that the program runs.

Complete Code

• Find every line that begins with the comment Fill Code: and read the description. Then, replace every instance of the comment UNCOMMENT AND COMPLETE with the appropriate line of code.

  /* Fill Code:
      .
      .
      .
  */
  /* UNCOMMENT AND COMPLETE: */
  

• The position of the box at the place location is saved in the global variable cfg.BOX_PLACE_TF.

• setOrigin() and setRotation() methods enable the modification of the place transform.

• The createManipulationPoses() uses the values of the approach and retreat distances in order to create the corresponding poses at the desired target.

Build Code and Run

• Compile the pick and place node:

  • In QTCreator: Build ‣ Build Project

  • Alternatively, in a terminal:

    colcon build
    

• Run the supporting nodes with the launch file (only if needed):

  ros2 launch pick_and_place_application application_setup.launch.py
  

• In another terminal, run your node with the launch file:

  ros2 launch pick_and_place_application application_run.launch.py
  

• The TCP and wrist positions at the place location will be printed on the terminal. You should see something like this:

  [INFO] [1400556479.404574973] [pick_and_place_node]: Pick Move 2 Succeeded
  [INFO] [1400556479.404866351] [pick_and_place_node]: tcp position at place: [-0.4, 0.6, 0.17]
  [ERROR] [1400556479.404981729] [pick_and_place_node]: doBoxPlace is not implemented yet.  Aborting.
  

API References

• setOrigin()

• setRotation()