Panda Arm - Franka Emika

This repository contains the application code used to communicate with the Franka Emika arm from Drake.

Building the driver

Before you begin, install the prerequisite:

sudo apt install libgflags-dev

To build, run bazel build //.... This will output two versions of the driver: bazel-bin/franka-driver/franka_driver_v4 and bazel-bin/franka-driver/franka_driver_v5.

Use franka_driver_v5 for the FR-3 robots.

Running the driver

You can run the driver via bazel run (recommended) or using the built binary in bazel-bin.

When using bazel run, remember to separate Bazel flags from program flags with --.

Common commands

Run the v4 driver (Franka Panda) in position mode using a torque-based position controller and vacuum gripper:

bazelisk run //franka-driver:franka_driver_v4 -- \
  --use_mbp \
  --expire_sec=0.05 \
  --robot_ip_address=192.168.0.2 \
  --control_mode=position \
  --use_torque_for_position=true \
  --vacuum

You can use the V5 Driver if using the FR3

Start the status subscriber / shared-memory bridge:

bazelisk run //franka-driver:panda_status_drake_subscriber_main

Optional verbose debug output for the subscriber:

bazelisk run //franka-driver:panda_status_drake_subscriber_main -- --debug

Flag reference (driver)

• --robot_ip_address=STRING: IP address of the robot controller (required).
• --control_mode=STRING: One of status_only, velocity, position, torque.
• --expire_sec=DOUBLE: Max command staleness allowed before rejecting commands.
• --use_mbp: Load a Drake MultibodyPlant model for internal dynamics computations.
• --use_torque_for_position: In position mode, use a torque controller to track positions.
• --vacuum (alias --vacumm): Use the vacuum gripper instead of the parallel gripper.
• --gripper_ip_address=STRING: Override the IP for the gripper device (defaults to robot IP).
• --lcm_gripper_command_channel=STRING: LCM channel for gripper/vacuum commands (default PANDA_GRIPPER_COMMAND).

Flag reference (subscriber)

• --debug: Enable verbose prints for the Panda status subscriber and shared-memory writes.

Notes on binaries

• franka_driver_v4 should be used with FE-3 firmware (libfranka v0.8.x).
• franka_driver_v5 should be used with FR-3 firmware (libfranka v0.10.x).

To run using the built binary directly (without bazel run):

bazel-bin/franka-driver/franka_driver_v5 --expire_sec=0.05 --robot_ip_address=<ip-addr> --control_mode=position

To add a gripper model to a simulation or directives file, update the relevant model directives.

Links

• Website
• Franka Control Interface (FCI) Documentation
• libfranka API Docs
• Panda datasheet

Notes

• Be sure to read the manual, FCI docs, etc.
  • The FCI docs have excellent instructions for getting your network interface on Ubuntu set up.
• There are two very distinct versions of Pandas: the FE3 (older) and FR3 (newer)
• There are three version to think about: firmware on the robot (we use v4.x, and v5.x) and libfranka driver software on the host PC (0.8.0 for v4.x FE3, and 0.10.0 for v5.x FR3).

  • You should see suffixes like _v4 and _v5 for relevant libraries and binaries.

  • If you use the wrong driver, you should get an error like:

      terminate called after throwing an instance of 'franka::IncompatibleVersionException'
      what():  libfranka: Incompatible library version (server version: 4, library version: 5). Please check https://frankaemika.github.io for Panda system updates or use a different version of libfranka.