Running the gripper on real equipment

[PartyKusZ]

Hi,
I've been trying to get the ability to control the grapple on real equipment for a while now, but I'm not able to and I keep failing all the time. Please give me some advice.
ROS melodic
Ubuntu 18.04
gripper 85
ur3 robot
Greetings,
Kuba

[cambel]

Hi @PartyKusZ,

I have added support for the real Robotiq gripper. You need to checkout the latest commit of this repository and move to the branch noetic-real-test in the robotiq package

Then you need to set the argument gripper of the Arm as '85'.

Try and let me know if you have problems with it. I have been using it and it works fine.

[PartyKusZ]

I am not sure how to make this change:
"Then you need to set the argument gripper of the Arm as '85'."
Can you tell me how to make this change?
Thank you

[cambel]

See this example

ur3/ur_control/scripts/joint_position_keyboard.py

Lines 207 to 211 in b3e1bdc

	arm = Arm(ft_sensor=False,
	gripper=use_gripper, namespace=ns,
	joint_names_prefix=joints_prefix,
	robot_urdf=robot_urdf, robot_urdf_package=rospackage,
	ee_link=tcp_link)

Change gripper=use_gripper to gripper='85'

[PartyKusZ]

When i ran it:
$ rosrun ur_control joint_position_keyboard.py
i recived errors:

Import ur_ikfast not available, IKFAST would not be supported without it ft_sensor: False, ee_link: None, robot_urdf: ur3e connecting to: /ur3/scaled_pos_joint_traj_controller/command [INFO] [1689848848.862789]: JointTrajectoryController initialized. ns: /ur3/

File "/home/lab010/catkin_workspace/src/ur3/ur_control/scripts/joint_position_keyboard.py", line 218, in <module> main()

File "/home/lab010/catkin_workspace/src/ur3/ur_control/scripts/joint_position_keyboard.py", line 211, in main ee_link=tcp_link)

File "/home/lab010/catkin_workspace/src/ur3/ur_control/src/ur_control/arm.py", line 106, in __init__ self._init_controllers(gripper, joint_names_prefix)

File "/home/lab010/catkin_workspace/src/ur3/ur_control/src/ur_control/arm.py", line 131, in _init_controllers self.gripper = GripperController(namespace=self.ns, prefix=self.joint_names_prefix, timeout=2.0)

File "/home/lab010/catkin_workspace/src/ur3/ur_control/src/ur_control/controllers.py", line 28, in __init__ self.gripper_type = str(rospy.get_param(self.ns + node_name + "/gripper_type"))

File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/client.py", line 467, in get_param return _param_server[param_name] #MasterProxy does all the magic for us
File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/msproxy.py", line 123, in __getitem__ raise KeyError(key)

KeyError: '/ur3/gripper_controller/gripper_type'
I changed the namespace directly in the code, from the namespace ur3 is running the ros drivers for ur3.

    ns = '/ur3'
    joints_prefix = None
    robot_urdf = "ur3e"
    rospackage = None
    tcp_link = None
    use_gripper = args.gripper
    global arm
    arm = Arm(ft_sensor=False,
              gripper='85', namespace=ns,
              joint_names_prefix=joints_prefix,
              robot_urdf=robot_urdf, robot_urdf_package=rospackage,
              ee_link=tcp_link)

[jabandersnatch]

Hi, first of all I'm really thankfull for all the development that you made for the UR3 robot, without you I could possibly be able to make my undergraduate project. I want to know If it's possible to run the hande robtiq gripper, with the UR3 and what are the steps to do that.

I tried to run the ur_driver package to my robot to no avail.

[cambel]

@PartyKusZ
I just noticed that you are working on ROS Melodic.
I have not tested working with the real gripper on Melodic, it should work but you would need to adapt the code, I don't have the time right now to add compatibility to Melodic.

[cambel]

Hi @jabandersnatch,

You could try to follow the steps that I mentioned in this issue to make it work with the Hand-e. It should work, but I haven't tested it and you would need to do some modifications. If you face any issue you can post it here, I can try to guide you.

On the other hand, I did try this other method a few years back.
Install this package and see the example in the script
https://github.com/cambel/ros_robotiq_urcap_control

[PartyKusZ]

@cambel
I informed you about the fact that I work in Melodic in the first message.
Thank you for your help.
Greetings

[PartyKusZ]

Hi @cambel !
I'm back after the vacation :D Referring to our earlier conversation:
I installed ubuntu 20.04 lts and ros noetic. I tried to switch to the noetic-real-test branch, but from what I saw it is no longer there, I suspect that everything needed to move the actual gripper is on the noetic-devel branch. I changed the configurations in the ur3/ur_control/scripts/joint_position_keyboard.py:

arm = Arm(ft_sensor=False,
              gripper='85', namespace=ns,
              joint_names_prefix=joints_prefix,
              robot_urdf=robot_urdf, robot_urdf_package=rospackage,
              ee_link=tcp_link)

file but I still can't close the gripper.
First I run roslaunch ur_robot_driver ur3_bringup.launch robot_ip:=192.168.10.200
and then roslaunch ur_gripper_85_moveit_config start_moveit.launch config:=true

Errors from roslaunch ur_robot_driver ur3_bringup.launch robot_ip:=192.168.10.200:

[ERROR] [1694420136.134940084]: A controller named 'scaled_pos_joint_traj_controller' was already loaded inside the controller manager
[ERROR] [1694420137.147607683]: Could not load controller 'gripper_controller' because the type was not specified. Did you load the controller configuration on the parameter server (namespace: '/gripper_controller')?

Errors from roslaunch ur_gripper_85_moveit_config start_moveit.launch config:=true
:
[ERROR] [1694422484.817733171]: Action client not connected: gripper_controller/gripper_cmd

[ERROR] [1694420332.871739267]: Known controllers and their joints:
controller 'scaled_pos_joint_traj_controller' controls joints:
  elbow_joint
  shoulder_lift_joint
  shoulder_pan_joint
  wrist_1_joint
  wrist_2_joint
  wrist_3_joint

[ERROR] [1694420332.871757695]: Apparently trajectory initialization failed

Wranings from roslaunch ur_gripper_85_moveit_config start_moveit.launch config:=true:
[ WARN] [1694420348.257971341]: The complete state of the robot is not yet known. Missing robotiq_85_left_knuckle_joint

Greetings

[cambel]

Hi @PartyKusZ ,
you are right, I moved it to the noetic-devel branch.

Sorry, I forgot to mention that you need to add the setup of the gripper to any of your launch files

  <include file="$(find robotiq_control)/launch/urcap_cmodel_action_controller.launch">
    <arg name="address" value="192.168.10.200" />
    <arg name="config" value="cmodel_action_controller_85" />
  </include>

[PartyKusZ]

@cambel
I added the following code:

<include file="$(find robotiq_control)/launch/urcap_cmodel_action_controller.launch">
    <arg name="address" value="192.168.10.200" />
    <arg name="config" value="cmodel_action_controller_85" />
</include>

to ros_ur3/ur_gripper_85_moveit_config/launch/start_moveit.launch

I get the same errors and warnings as before from roslaunch ur_gripper_85_moveit_config start_moveit.launch config:=trueand new one:Failed to activate gripper in ns [/gripper/]

Tell me please how you run ROS packages to move the real ur3 and gripper. Perhaps I was making some obvious mistake. Thank you for all your help. Greetings

[PartyKusZ]

Hi @cambel
I discovered a new problem. When I run the gripper directly in ur3 computer and then try to run roslaunch ur_gripper_85_moveit_config start_moveit.launch config:=true I get this error: Joint 'finger_joint' not found in model 'ur_robot_gazebo'.
Greetings.

[cambel]

@PartyKusZ

This is what I usually do to connect to the real robot and the gripper:

1. Launch a bringup.launch file that is modified to load the URDF that includes the gripper.
2. Launch or include in the previous file the configuration for the gripper
3. Test manually using rqt tools

I created a new branch called real-robot. In that, I added a configuration to hopefully connect the robot and the gripper.
Use roslaunch ur3_description bringup_with_gripper_85.launch robot_ip:=<<your_ip>>

I have not tested it. I will try to test it with the real robot sometime next week.
If you try it, let me know the results

[PartyKusZ]

@cambel
I tested it. I got following error:

Arg xml is <arg name="kinematics_params" value="$(arg kinematics_config)"/>
The traceback for the exception was written to the log file

[cambel]

@PartyKusZ

I finally had time to test it on the real robot.
I made several modifications so if you can try again, check the latest commit on the real-robot branch.
Also, you need to move the robotiq package to the noetic-real-robot branch so that they can work together.