Gripper

This page describes the Gripper step of a solution, where you add a gripper, upload its CAD model and select the gripper the robot uses. It applies to Bin Picking Studio (BPS) solutions only, the CAD Picking and AI Picking solution types.

Gripper list

The Gripper page lists all grippers available in the Studio. Grippers are shared between solutions, so a gripper added in one solution can be selected in any other solution.

Gripper page with the selected gripper and Add a gripper

The Gripper page. Red frames: the selected gripper (green), Add a gripper, and the Select, Edit, Duplicate and Delete buttons of a gripper.

Each gripper shows its name, an image and the status of its tool point (Created or Not created). The Cards view and Table view buttons switch between two layouts of the list.

The page offers these actions:

  • Add a gripper - creates a new gripper.

  • Select - makes the gripper the gripper of the current solution.

  • Edit - opens the gripper form (see Gripper form).

  • Duplicate - creates a copy of the gripper.

  • Delete - removes the gripper.

Custom grippers are designated by a blue frame. Default grippers cannot be edited. To change a default gripper, duplicate it first. The copy is a custom gripper, which can be edited.

Selecting a gripper

To choose the gripper of the solution, click Select on the gripper and confirm the message.

When you select a gripper, the Studio makes these changes automatically:

  • The calibration point dataset will be removed in all vision systems.

  • Automatic calibration feature will be disabled in all vision systems.

Because the calibration point datasets are removed and automatic calibration is disabled, calibrate the vision systems again after you change the gripper. See Calibration.

Gripper form

The gripper form has two tabs: Model and Tool point.

Model tab

Gripper form with the Model and Tool point tabs and the CAD file field

The gripper form. Red frames: the Model and Tool point tabs and the CAD file (mesh) field.

The Model tab has these fields:

  • Name (required)
    The name of the gripper.
  • CAD file (mesh) (required, .stl)
    “A CAD model is necessary for the program to calculate valid paths with real collision avoidance. CAD model dimension unit has to be in millimeters. Also, don’t forget to include any extra gear (such as split-boxes, valves) on the gripper model so that the robot will take them into account during path planning.”
  • Image (.jpg, .jpeg, .gif or .png)
    A picture of the gripper shown in the gripper list. If you do not upload an image when creating a new gripper, the image is generated automatically from the STL model. To replace your own image with a generated one, click Delete next to the current image.

Click Save to store the changes.

Next to the form, a 3D viewer shows the gripper model. The Preview tool point invariance pose slider in the viewer lets you preview the poses of the tool point invariance. For what invariances are, see Invariance.

Note: The origin of the gripper model (point [0,0,0] in your file) should be exactly at the mounting point of the gripper. The system attaches the origin of the gripper model to the endpoint of the robotic arm. The Z-axis of the endpoint keeps the direction of the last element.

You can check the model alignment on the Environment page.

Tool point

The tool point of the gripper is defined on the Tool point tab of the gripper form. The tool point is the point on the gripper that meets a gripping point of the picked object during grasping.

Tool point tab of the gripper form with position, rotation and rotation invariance fields

The Tool point tab. Red frames: the tab and the position and rotation of the tool point. The 3D viewer on the right shows the tool point.

The tab has these fields:

  • Position X [mm], Position Y [mm], Position Z [mm] – the position of the tool point.

  • Rotation X [°], Rotation Y [°], Rotation Z [°] – the rotation of the tool point, each in the range -180 to 180.

  • Enable rotation invariance – turns on the rotation invariance of the tool point. The invariance is set on the Basic Mode or Advanced Mode tab below the checkbox.

On the Basic Mode tab:

  • Rotation invariant around axis – X-axis, Y-axis or Z-axis.

  • Rotation lower limit [°] and Rotation upper limit [°] – each in the range -360 to 360.

  • Rotation number of steps – in the range 2 to 36. One numbered button is shown for each step, with Enable all and Disable all below them.

Click Save to store the tool point.

For the definition of the tool point, its invariances and examples for common grippers, see Tool point and gripping point and Example tool points on the Gripping points page.