external-gripper-example

This repository provides example code on how Panda can be controlled via franka_ros in combination with an external gripper. In this particular example, the Robotiq 2F-85 gripper is used mounted on the flange of the Panda (see panda_with_robotiq_gripper_example.png). The package allows the user to run a configurable pick-and-place example sequence. This software is tested with the following dependency version:

• libfranka == 0.5.0
• franka_ros == 0.6.0
• robotiq_2finger_grippers == 0.9.1
• panda_moveit_config == 0.7.2

For the installation of 'libfranka', 'franka_ros' and panda_moveit_config please refer to Franka Control Interface Documentation. In our example we use the following repo to control the Robotiq 2F-85 gripper:

https://github.com/Danfoa/robotiq_2finger_grippers

Note: The are other options of ros_packages for robotiq gripper like the official ROS drivers from Robotiq.

Deployment

1: Start your Panda and make sure that your end-effector settings match the Robotiq 2F-85 gripper's values in Desk. See Franka Control Interface Documentation on how to accomplish this. For faster deployment you can ``uploadpredefined settings inDesk` derived from the 2F-85 manual. The file is located here:

panda_with_robotiq_gripper_example/config/endeffector-config.json

2: Connect the gripper to your PC via USB. In our setup we use e.g. a Robotiq K-1444 Universal Controller which is connected via USB to the control PC. See Robotiq's support page for further information (https://robotiq.com/de/produkte/adaptiver-2-finger-robotergreifer-2f85-140).

3: Install all dependencies, set up your workspace and build it:

   sudo usermod -a -G dialout <your_username>  # Your user must be in the dialout group to connect to USB ports
   sudo apt install ros-kinetic-libfranka      # If not already installed
   sudo apt install ros-kinetic-franka-ros
   mkdir -p catkin_ws/src                      # Create a folder for your workspace
   cd catkin_ws/src
   git clone https://github.com/Danfoa/robotiq_2finger_grippers.git
   git clone https://github.com/ros-planning/panda_moveit_config.git
   git clone https://github.com/frankaemika/external_gripper_example.git
   cd ..
   source /opt/ros/kinetic/setup.bash
   catkin_make
   source devel/setup.bash

4: Launch the example application with

roslaunch panda_with_robotiq_gripper_example panda_with_robotiq_gripper_example.launch robot_ip:=<robot-ip> gripper_dev_name:=<usb-bus-of-the-gripper>

Note: You need pass the USB-bus to which the gripper is connected to the launch file. You can find out where you connected the gripper with the lsusb command(e.g. "/dev/ttyUSB1").

Customization

Each of the sequential steps of the pick-and-place demo are described in the file:

panda_with_robotiq_gripper_example/config/pick_and_place.yaml

Feel free to customize them to configure your own sequence. The panda_with_robotiq_gripper_example/scripts/panda_with_robotiq_gripper_example.py script will process them. It supports 4 possible steps:

• moveit_cart: Go to a specific Cartesian pose using MoveIt!.
• moveit_joint: Go to a specific joint configuration using MoveIt!.
• gripper_move: Move the Robotiq 2F-85 gripper to a specific gripper position between 0.0: closed and 1.0: open.
• set_collision_behavior: Set the collision behavior for the Panda robot.