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Saif Sidhik edited this page May 27, 2021 · 2 revisions

NOTE: For using this package with Panda Simulator, the following sections are not required; all the required "driver" nodes are started along with the simulation launch file, and the Franka ROS Interface API (as well as PandaRobot API) can be directly used. Follow instructions in the demos section in the Panda Simulator package. See their corresponding source files for usage examples.

The franka.sh environments

Once the values are correctly modified in the franka.sh file (see Installation), different environments can be set for controlling the robot by sourcing this file.

  • For instance, running ./franka.sh master would start an environment assuming that the computer is directly connected to the robot (requires Real-Time kernel set up as described in the FCI documentation).
  • On the other hand, ./franka.sh remote would start an environment assuming that the robot is not connected directly to the computer, but to another computer in the network (whose IP must be specified in franka.sh). This way, if the 'master' is connected to the robot and running the driver node (see below), the 'remote' can control the robot (no need for Real Time kernel!) as long as they are in the same network.
  • Simulation environment can be started by running ./franka.sh sim (only required when using panda_simulator package). Not required anymore

More information regarding the usage of franka.sh can be found within the franka.sh file.

Starting the Franka ROS Interface 'Driver'

The 'driver' node can be started by running (can only be used if run in 'master' environment - see Environments section above):

    roslaunch franka_interface interface.launch # (use argument load_gripper:=false for starting without gripper)

Available keyword arguments for launch file:

  • load_gripper: start driver node with the Franka gripper (default: true).
  • start_controllers: load the available controllers to the controller manager (default: true).
  • start_moveit: start moveit server along with the driver node (default: true).
  • load_demo_planning_scene: loads a default planning scene for MoveIt planning with simple objects for collision avoidance (default: true). See create_demo_planning_scene.py.

This starts the robot controllers and drivers to expose a variety of ROS topics and services for communicating with and controlling the robot.

Controlling and Monitoring the Robot

Once the 'driver' is running, the robot can be controlled from another terminal by running in 'master' environment (if running in the same machine as 'driver'), or 'remote' environment (if using a different connected computer). The robot can then be controlled and monitored using ROS topics and services (see below to find out about some of the available topics and services), or using the provided Python API (also see PandaRobot).

Example of the robot working with MoveIt can be found by running roslaunch franka_moveit demo_moveit.launch.

Basic usage of the Python API is shown in the demo_interface.py example file. An example of controlling the robot joints with keyboard using direct position control is shown in demo_joint_positions_keyboard.py (read the notes in the file before running the demo. start this demo by running rosrun franka_interface joint_position_keyboard.py).

See documentation for all available methods and functionalities.

See the tests and scripts directories in franka_interface for few more usage examples.

More usage examples can be found in the PandaRobot package.

Some useful ROS topics

Published Topics
ROS Topic Data
/franka_ros_interface/custom_franka_state_controller/robot_state gravity, coriolis, jacobian, cartesian velocity, etc.
/franka_ros_interface/custom_franka_state_controller/tip_state end-effector pose, wrench, etc.
/franka_ros_interface/joint_states joint positions, velocities, efforts
/franka_ros_interface/franka_gripper/joint_states joint positions, velocities, efforts of gripper joints
Subscribed Topics
ROS Topic Data
/franka_ros_interface/motion_controller/arm/joint_commands command the robot using the currently active controller
/franka_ros_interface/franka_gripper/[move/grasp/stop/homing] (action msg) command the joints of the gripper

Other topics for changing the controller gains (also dynamically configurable), command timeout, etc. are also available.

ROS Services

Controller manager service can be used to switch between all available controllers (joint position, velocity, effort). Gripper joints can be controlled using the ROS ActionClient. Other services for changing coordinate frames, adding gripper load configuration, etc. are also available.

Python API

Most of the above services and topics are wrapped using simple Python classes or utility functions, providing more control and simplicity. This includes direct control of the robot and gripper using the provided custom low-level controllers, MoveIt, and JointTrajectoryAction. Refer README files in individual subpackages.

Documentation

More usage examples in the PandaRobot package.