Install Robotiq 2F gripper on UR robot

1. Conditions

  • OS: Ubuntu 20.04.5 LTS 64-bit
  • Robot: UR10 (CB series)
  • Polyscope version: 3.15.8

  • For CB series, you should connect the USB cord of the gripper to the remote PC, rather than to the control box.

    If you are using e-series, it seems possible to connect the USB to the control box and to control the gripper from a remote PC. Please refer to this and this.

2. Installation

Please follow this.

When you get an queue_size error, please refer to this.

# The Gripper status is published on the topic named 'Robotiq2FGripperRobotInput'
    pub = rospy.Publisher(
        "Robotiq2FGripperRobotInput", inputMsg.Robotiq2FGripper_robot_input, queue_size=10
    )

3. Running the gripper

First of all, please turn on the power supply to give 24 VDC (Set the maximum voltage as 24V and the maximum current as 1.0 A, and volatge control mode), and check if you can see either blue or led light on the gripper.

Open a terminal and run

$ roscore

Open another terminal and run

$ rosrun robotiq_2f_gripper_control Robotiq2FGripperRtuNode.py /dev/ttyUSB0

Open another terminal and run rosrun robotiq_2f_gripper_control Robotiq2FGripperSimpleController.py

If you see the queue_size error message, such as below:

$ rosrun robotiq_2f_gripper_control Robotiq2FGripperSimpleController.py

/home/softtas2022/catkin_ws/src/robotiq/robotiq_2f_gripper_control/nodes/Robotiq2FGripperSimpleController.py:135: SyntaxWarning: The publisher should be created with an explicit keyword argument 'queue_size'. Please see http://wiki.ros.org/rospy/Overview/Publishers%20and%20Subscribers for more information.
  pub = rospy.Publisher(
Simple 2F Gripper Controller
-----
Current command:  rACT = 0, rGTO = 0, rATR = 0, rPR = 0, rSP = 0, rFR = 0
-----
Available commands

r: Reset
a: Activate
c: Close
o: Open
(0-255): Go to that position
f: Faster
l: Slower
i: Increase force
d: Decrease force
-->

In this case, please open Robotiq2FGripperSimpleController.py in ~/catkin_ws/src/robotiq/robotiq_2f_gripper_control/nodes/ and add queue_size=10, such as below

...
# The Gripper status is published on the topic named 'Robotiq2FGripperRobotInput'
    pub = rospy.Publisher(
        "Robotiq2FGripperRobotInput", inputMsg.Robotiq2FGripper_robot_input, queue_size=10
    )
...

4. Issue - gFLT = 14: Overcurrent protection triggered

The gripper’s listener provides the gripper’s status.

$ rosrun robotiq_2f_gripper_control Robotiq2FGripperStatusListener.py

Whenever the grippers light blinks in blue and red colors, check the status using the listener.

I found “gFLT = 14: Overcurrent protection triggered” whenever I activated the gripper. I guess the current gets over the limit internally defined if

  • the gripper wants to reach the 0 gap even if our gripper hardly grips to 0. (Overcurrent)
  • the gripper want to reach the 255 gap even if our gripper hardly grips to 255. (Overcurrent)
  • the gripper could not produce higher current when closing it. (Undercurrent)

4.1. Overcurrent case

My solution is to set the gripper work within 10 - 250. In addition, decrease the force and speed.

4.2. Undercurrent case

Set the maximum current as 1.2 A in the DC power supply (although the official manual indicates 1.0 A), and the maximum voltage as 24 V.

5. Simple Python code to control the gripper

Please see this repository.