Control Robotiq 2F-85 gripper on UR5e

[Yeesha-R]

Affected ROS Driver version(s)

ROS noetic

Used ROS distribution.

Noetic

Which combination of platform is the ROS driver running on.

Linux with realtime patch

How is the UR ROS Driver installed.

Build the driver from source and using the UR Client Library from binary

Which robot platform is the driver connected to.

Real robot

Robot SW / URSim version(s)

5.12.4

How is the ROS driver used.

Through the robot teach pendant using External Control URCap

Issue details

Summary

I am unable to control the Robotiq 2F-85 gripper directly connected to the tool flange of my UR5e robotic arm.

Issue details

I have a setup in which the 2f-85 gripper is directly attached to the tool flange of my UR5e robot arm. I am relatively new to ROS, but I have read most issues on this topic, including #240 but I still get errors. Kindly correct me if I am wrong, but my understanding is to run the codes in the following order:

1. roslaunch ur_robot_driver ur5e_bringup.launch robot_ip:=192.168.1.2 kinematics_config:=$(rospack find ur_calibration)/my_robot_calibration.yaml use_tool_communication:=true tool_device_name:=/tmp/ttyUR tool_voltage:=24
2. rosrun robotiq_2f_gripper_control Robotiq2FGripperRtuNode.py /tmp/ttyUR
3. rosrun ur_robot_driver tool_communication

Steps to Reproduce

To start the robotic arm, I run roslaunch ur_robot_driver ur5e_bringup.launch robot_ip:=192.168.1.2 kinematics_config:=$(rospack find ur_calibration)/my_robot_calibration.yaml use_tool_communication:=true tool_device_name:=/tmp/ttyUR tool_voltage:=24

This creates a file named 'ttyUR' in my tmp folder.

However, when I run rosrun robotiq_2f_gripper_control Robotiq2FGripperRtuNode.py /tmp/ttyUR, I encounter the following error and notice that the ttyUR file created in my tmp folder gets deleted

Traceback (most recent call last):
File "/home/ubuntu/catkin_ws/src/robotiq/robotiq_2f_gripper_control/nodes/Robotiq2FGripperRtuNode.py", line 89, in
mainLoop(sys.argv[1])
File "/home/ubuntu/catkin_ws/src/robotiq/robotiq_2f_gripper_control/nodes/Robotiq2FGripperRtuNode.py", line 75, in mainLoop
status = gripper.getStatus()
File "/home/ubuntu/catkin_ws/src/robotiq/robotiq_2f_gripper_control/src/robotiq_2f_gripper_control/baseRobotiq2FGripper.py", line 107, in getStatus
status = self.client.getStatus(6);
File "/home/ubuntu/catkin_ws/src/robotiq/robotiq_modbus_rtu/src/robotiq_modbus_rtu/comModbusRtu.py", line 94, in getStatus
response = self.client.read_holding_registers(0x07D0, numRegs, unit=0x0009)
File "/home/ubuntu/.local/lib/python3.8/site-packages/pymodbus/client/mixin.py", line 107, in read_holding_registers
return self.execute(
File "/home/ubuntu/.local/lib/python3.8/site-packages/pymodbus/client/base.py", line 391, in execute
raise ConnectionException(f"Failed to connect[{self!s}]")
pymodbus.exceptions.ConnectionException: Modbus Error: [Connection] Failed to connect[ModbusSerialClient /tmp/ttyUR:0]

I have also modified my launch file as follows:

<?xml version="1.0"?>
<launch>
  <arg name="debug" default="false" doc="Debug flag that will get passed on to ur_common.launch"/>
  <arg name="robot_ip" default="192.168.1.2" doc="IP address by which the robot can be reached."/>
  <arg name="reverse_ip" default="" doc="IP of the driver, if set to empty it will detect it automatically."/>
  <arg name="reverse_port" default="50001" doc="Port that will be opened by the driver to allow direct communication between the driver and the robot controller."/>
  <arg name="script_sender_port" default="50002" doc="The driver will offer an interface to receive the program's URScript on this port. If the robot cannot connect to this port, `External Control` will stop immediately."/>
  <arg name="trajectory_port" default="50003" doc="Port that will be opened by the driver to allow trajectory forwarding."/>
  <arg name="script_command_port" default="50004" doc="Port that will be opened by the driver to allow forwarding script commands to the robot."/>
  <arg name="tf_prefix" default="" doc="tf_prefix used for the robot."/>
  <arg name="controllers" default="pose_based_cartesian_traj_controller scaled_pos_joint_traj_controller joint_state_controller speed_scaling_state_controller force_torque_sensor_controller" doc="Controllers that are activated by default."/>
  <arg name="stopped_controllers" default="joint_based_cartesian_traj_controller forward_cartesian_traj_controller pos_joint_traj_controller joint_group_vel_controller" doc="Controllers that are initally loaded, but not started."/>
  <arg name="controller_config_file" default="$(find ur_robot_driver)/config/ur5e_controllers.yaml" doc="Config file used for defining the ROS-Control controllers."/>
  <arg name="robot_description_file" default="$(find ur_description)/launch/load_ur5e.launch" doc="Robot description launch file."/>
  <arg name="kinematics_config" default="$(find ur_description)/config/ur5e/my_robot_calibration.yaml" doc="Kinematics config file used for calibration correction. This will be used to verify the robot's calibration is matching the robot_description."/>
  <arg name="use_tool_communication" default="true" doc="On e-Series robots tool communication can be enabled with this argument"/>
  <arg name="tool_voltage" default="24" doc="Tool voltage set at the beginning of the UR program. Only used, when `use_tool_communication` is set to true."/>
  <arg name="tool_parity" default="0" doc="Parity configuration used for tool communication. Only used, when `use_tool_communication` is set to true."/>
  <arg name="tool_baud_rate" default="115200" doc="Baud rate used for tool communication. Only used, when `use_tool_communication` is set to true."/>
  <arg name="tool_stop_bits" default="1" doc="Number of stop bits used for tool communication. Only used, when `use_tool_communication` is set to true."/>
  <arg name="tool_rx_idle_chars" default="1.5" doc="Number of idle chars in RX channel used for tool communication. Only used, when `use_tool_communication` is set to true."/>
  <arg name="tool_tx_idle_chars" default="3.5" doc="Number of idle chars in TX channel used for tool communication. Only used, when `use_tool_communication` is set to true."/>
  <arg name="tool_device_name" default="/tmp/ttyUR" doc="Local device name used for tool communication. Only used, when `use_tool_communication` is set to true."/>
  <arg name="tool_tcp_port" default="54321" doc="Port on which the robot controller publishes the tool comm interface. Only used, when `use_tool_communication` is set to true."/>
  <arg name="headless_mode" default="true" doc="Automatically send URScript to robot to execute. On e-Series this does require the robot to be in 'remote-control' mode. With this, the URCap is not needed on the robot."/>
  <arg name="ur_hardware_interface_node_required" default="true" doc="Shut down ros environment if ur_hardware_interface-node dies."/>

  <include file="$(find ur_robot_driver)/launch/ur_common.launch" pass_all_args="true" />
</launch>

Expected Behavior

To establish a connection to the gripper without error

Actual Behavior

Unable to establish a connection with the gripper.

Kindly let me know if you need any more information. Thank you.

Relevant log output

No response

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• [X] I agree to make this context public

[RobertWilbrandt]

The order you describe in "Issue details" seems wrong to me. Passing use_tool_communication:=true to ur5e_bringup.launch should already start socat in the tool_communication script (see here), so your explicit call to it seems superfluous. Regardless, you should only start the gripper driver after you started socat, but this would lead to a different error.

Did you set up the tool I/O on the teach pendant correctly? We currently have a setup with a ur5e and a robotiq 2f-140 connected to its tool connector and under installation->Tool I/O we configured the following settings:

• Controlled by: User
• Analog Inputs - Communication Interface
  • Communication Interface (Baud rate 115200, Parity None, Stop Bits One, RX Idle Chars 1.5, TX Idle Chars 3.5)
• Digital Output Mode
  • Digital Output Mode - Tool Output Voltage: 0
  • Dual Pin Power

Did you make sure no other URCap is installed that could interfere with the driver? In particular, you need to remove the robotiq URCap.

[Yeesha-R]

@RobertWilbrandt, thank you for your response. I followed your instructions and adjusted the settings on my teach pendant, successfully launching the robot and executing rosrun ur_robot_driver tool_communication. However, I encountered an error when attempting to run rosrun robotiq_2f_gripper_control Robotiq2FGripperRtuNode.py :

Traceback (most recent call last):
  File "/home/ubuntu/catkin_ws/src/robotiq/robotiq_2f_gripper_control/nodes/Robotiq2FGripperRtuNode.py", line 92, in <module>
    mainLoop(sys.argv[1])
IndexError: list index out of range

Despite my attempts to debug the code, I have been unable to resolve the issue. I apologize for any repetition, as I am not well-versed in this area. Could you let me know if I am supposed to run rosrun robotiq_2f_gripper_control Robotiq2FGripperRtuNode.py ? If not, could you please provide guidance on how to communicate with the robot once the connection is established?

Thank you so much for your assistance.

[RobertWilbrandt]

Glad to hear that tool forwarding now seems to work for you. I am not aware of the error you are seeing now, looking back at the last time we used this gripper in ROS 1 (our current setup uses ROS 2) that was the node we started.

I think you need to pass the serial device (i.e. /tmp/ttyUR) to the rosrun command as you described above to get through this error.

[Yeesha-R]

Okay, thanks @RobertWilbrandt

[fmauch]

@Yeesha-R Does hat mean the issue is resolved for you and can be closed?