ROS2 and Ignition support for Robotiq 2F-85 gripper???

bene

Hello,

I am thinking about purchasing a Robotiq 2F-85 gripper. I would like to mount it to a UR5 robot arm from Universal Robots and control it via ROS2. At the moment I am using Galactic Geochelone running on an Ubuntu 20.04 computer and as soon as the next LTS version is available, I will upgrade to that one (Humble Hawksbill). I am not new to robotics nor ROS, but it is the first time I am using an actual industrial robot arm. So maybe I have overseen something. I have the ROS2 package from Universal Robots installed. So maybe the URCap is solving my issue?

I am wondering if there is an official ROS2 package from Robotiq that allows to control the 2F-85 gripper? I have seen the ROS Industrial repository https://github.com/ros-industrial/robotiq but it seems that it is no longer maintained what made me a bit worried. Furthermore, I would prefer native ROS2 support instead of using a ROS1 to ROS2 bridge.

Another question is if I have to connect the gripper to the UR's control box or if I can control it independently using ROS2 just by installing a RS485 to USB converter and plug the USB connector into my computer?

On top of controlling the gripper, I would like to simulate it using Ignition Fortress (successor of Gazebo) and perform motion planning using Moveit2. Are there official instructions from Robotiq on how to do that? If not, what would be the best way to go?

Thanks for your support.

Best regards,
Benedikt

bcastets

Your post resume quite well the situation.
We have 2 types of gripper couplings. One to connect the gripper to the controller via RS485/USB converter and another to connect the gripper at the wrist of eSerie. The version directly connected to the controller is probably the most flexible because you can both connect on the UR controller or the ROS PC.
If you develop a ROS2 package place check it here so that other members of the community can contribute.

bcastets

There is no ROS2 package made by Robotiq at the moment. It is possible that other person from the community developped something. It should be not that complicate to develop a package.

The gripper can be connected on the UR robot or directly on the ROS PC. Direct connection on ROS PC via RS485éUSB converter is probably the easiest way to go. The current robotiq ROS package is design to work like this.

You can find more information about how to control a gripper connected to a UR robot in this post:
https://dof.robotiq.com/discussion/comment/7296#Comment_7296

As for the simulation in the current ros package I know we have some model but I am not just this will fit for you.

bene

Thank you for your quick answer.

So if I understand you correctly I have to download the URCap file from https://robotiq.com/support/2f85-140-adaptive-robot-gripper (see attached screenshot) and install it on the robot via the teach pendant.

This will install a URCap server that I can send commands to using your Python file from https://dof.robotiq.com/discussion/comment/7296#Comment_7296 . I can wrap the Python file into a ROS2 node in order to control the gripper with ROS2. In this first setup I have to connect the gripper to the control box of the UR with a serial connection as shown in this video https://www.youtube.com/watch?v=oDlAzFtKLMc and connect the UR control box via Ethernet with my ROS2 PC, right? So if I want a direct serial connection between the gripper and my ROS2 PC (using a RS485 to USB adapter) I have to follow the instructions of this post: https://dof.robotiq.com/discussion/1382/control-grippers-from-python-using-modbus-rtu#latest and this post: https://dof.robotiq.com/discussion/92/controlling-the-robotiq-2-finger-gripper-with-modbus-commands-in-python?_ga=2.17431289.1133307955.1542044765-1547192274.1535646624 . In this second setup I do not have to use any control box (neither the UR one nor the Robotiq universal control box) and also no URCap driver but I need a 24 VDC power supply, right? Are there any advantages/disadvantages between the two setups?

Regarding simulation I will most likely use the model provided from https://github.com/ros-industrial/robotiq and hope that the physics parameters are accurate enough.

bene

For both setups, there are ROS1 (Kinetic) implementations here https://wiki.ros.org/robotiq . Though they are not maintained anymore, this could be an alternative by using a ROS1 two ROS2 bridge.

As for the simulation I will most likely use the models provided here: https://github.com/ros-industrial/robotiq/tree/kinetic-devel/robotiq_2f_85_gripper_visualization . It is just not clear to me, how I can control the gripper in the simulation? In best case there is a way to control the gripper in the simulation the same way as in reality so that the sim to real transfer is as easy as possible. Any thoughts on that?

bene

For both setups, there are ROS1 (Kinetic) implementations here https://wiki.ros.org/robotiq . Though they are not maintained anymore, this could be an alternative by using a ROS1 two ROS2 bridge.

As for the simulation I will most likely use the models provided here: https://github.com/ros-industrial/robotiq/tree/kinetic-devel/robotiq_2f_85_gripper_visualization . It is just not clear to me, how I can control the gripper in the simulation? In best case there is a way to control the gripper in the simulation the same way as in reality so that the sim to real transfer is as easy as possible. Any thoughts on that?

bene

Thank you for your quick answer.

As I understand it I have two options to connect and control the gripper:

1) Connect the gripper to the UR5 and connect my ROS2 computer via Ethernet with the UR5 control box. In this case I have to follow the instructions in this video: https://www.youtube.com/watch?v=oDlAzFtKLMc and install the URCap file using the teach pendant. This sets up a URCap server that I can communicate with using your Python file from https://dof.robotiq.com/discussion/comment/7296#Comment_7296 . This Python file I can wrap into a ROS2 node so that I can control the gripper with ROS2.

2) Connect the gripper directly to my ROS2 computer using a RS485 to USB adapter and an external 24 VDC power supply. In this case I have to follow the instructions in these two posts: https://dof.robotiq.com/discussion/1382/control-grippers-from-python-using-modbus-rtu#latest and https://dof.robotiq.com/discussion/92/controlling-the-robotiq-2-finger-gripper-with-modbus-commands-in-python?_ga=2.17431289.1133307955.1542044765-1547192274.1535646624

Are there any advantages/disadvantages using either of the two setups?

There are ROS1 (Kinetic)  implementations for both setups here https://wiki.ros.org/robotiq . Though they are not maintained anymore, this could be an alternative if using a ROS1 two ROS2 bridge.

As for the simulation I will most likely use the models provided here: https://github.com/ros-industrial/robotiq/tree/kinetic-devel/robotiq_2f_85_gripper_visualization . It is just not clear to me, how I can control the gripper in the simulation? In best case there is a way to control the gripper in the simulation the same way as in reality so that the sim to real transfer is as easy as possible. Any thoughts on that?

bene

For both setups, there are ROS1 (Kinetic) implementations here https://wiki.ros.org/robotiq . Though they are not maintained anymore, this could be an alternative by using a ROS1 two ROS2 bridge.

As for the simulation I will most likely use the models provided here: https://github.com/ros-industrial/robotiq/tree/kinetic-devel/robotiq_2f_85_gripper_visualization . It is just not clear to me, how I can control the gripper in the simulation? In best case there is a way to control the gripper in the simulation the same way as in reality so that the sim to real transfer is as easy as possible. Any thoughts on that?