KUKA Pickit interface

This article documents the interface of the KUKA Pickit integration. For installation instructions, please refer to the KUKA installation and setup article.

Pickit communication functions

Below you find an overview of the functions defined by Pickit that are responsible for communicating with a Pickit system. For more details on these functions, refer to The Pickit interface.

Function Comment Input arguments Return type
Pickit_is_running() Check if Pickit is set to Robot mode. - Boolean
Pickit_do_calibration() Trigger a detection of the robot-camera calibration plate. - -
Pickit_look_for_object() Trigger a Pickit object detection using the currently active setup and product Configuration. - -
Pickit_detect_with_retr (LZ_Retries:IN) Repeatedly trigger a Pickit object detection as long as nothing is found and the ROI is not empty, up to a number of attempts. max number of retries -
Pickit_capture_image() Trigger Pickit to capture a camera image to be used by a following Pickit_process_image() function. - -
Pickit_process_image() Trigger an object detection on the camera image that was previously captured via the Pickit_capture_image() function (or one of the Detection functions). - -
Pickit_next_object() Request the next detected object. - -
Pickit_configure (LZ_Setup:IN,LZ_Product:IN) Load the specified setup and product Configuration. setup id, product id -
Pickit_save_scene() Save a snapshot with the latest detection results. - -
Pickit_build_bkg_cloud() Build the background cloud used by one of the Advanced filters. - -
Pickit_has_response() Returns true and updates results, if the Pickit detection is finished. Usually used inside a Wait command. Pickit_has_response() should always be the next Pickit function after a Pickit_look_for_object(), Pickit_next_object(), Pickit_detect_with_retr(..) or Pickit_process_image() request. - Boolean - (Some Pickit variables are updated in the background)
Pickit_get_results() Combination of Pickit_has_response() and Pickit_gppd() function. This function is not compatible with Pickit versions prior 2.2. - Boolean - (All Pickit variables are updated in the background)
Pickit_gppd() Request the pick point ID and pick point offset of the last requested object. This function is not compatible with Pickit versions prior 2.2. - - (Some Pickit variables are updated in the background)

Pickit helper functions

The following functions don’t communicate with Pickit, using the results of previous commands, but make your robot program more readable. The return values of these functions get updated after using the Pickit functions Pickit_has_response() or Pickit_get_results(). See KUKA example picking program on how they are typically implemented in a robot program.

Function Return value
Pickit_object_found() True if detection results are available.
Pickit_no_image_captured() True if no image was captured by Pickit. If so, check the camera connection.
Pickit_roi_empty() True if the ROI is empty.

Pickit output functions

The following functions are used to get the output values of Pickit. The output values are updated after using the Pickit function Pickit_has_response() or Pickit_get_results().

Function Return value Return type
Pickit_get_pose() Pick point expressed with respect to the robot base frame. FRAME
Pickit_get_offset() Pick point offset of the last requested object. FRAME
  • For a Teach detection, ID type of the detected object.
  • For a Flex/Pattern detection, the object type of the detected object.
  • In a Bags detection, a value holding information about the bag pattern and the detected layer orientation.
Pickit_object_pick_id() ID of the pick point that was selected for the previously sent object. INT
Pickit_object_age() Amount of time that has passed between the capturing of the camera image and the moment the object information is sent to the robot (s). REAL
Pickit_object_dim_1() Length or diameter (mm). REAL
Pickit_object_dim_2() Width or diameter (mm). REAL
Pickit_object_dim_3() Height (mm). REAL
Pickit_object_ref_id() ID of the selected pick point’s reference pick point. INT
Pickit_remaining_objects() Number of remaining objects that can be sent to the robot in the next messages. INT

More detailed information about these outputs can be found here.

Using pick offset in a robot program

When using multiple pick points or flexible pick orientations, it can be useful to use the pick offset from a reference/nominal pick point in order to correct a drop-off point. The following lines of code show how to correct the fixed point Dropit in a KUKA robot program:

drop_offset = Pickit_get_offset()
F_drop_correct = Dropit:drop_offset
PTP F_drop_correct