drake-franka-driver

Drake-compatible LCM driver for the Franka PANDA research robot. This driver uses the Franka Control Interface and is designed for use with the Drake planning and control toolbox.

Prerequisites

This C++ driver depends on drake and drake-lcmtypes. You may use our drake-torch images or install drake with the following.

curl -SL https://drake-packages.csail.mit.edu/drake/nightly/drake-20200530-bionic.tar.gz | tar -xzC /opt
cd /opt/drake/share/drake/setup && yes | ./install_prereqs

See drake-shambhala for more examples.

You also need the LCM library.

git clone https://github.com/lcm-proj/lcm
cd lcm && mkdir -p build && cd build && cmake ..
make install -j 12

drake has deprecated some lcmtypes needed here. The robot_msgs repo has a copy of them; only the headers in include/lcmtypes are needed. See .circleci/config.yml and CMakeLists.txt for details.

Building the driver

git clone --recursive https://github.com/DexaiRobotics/drake-franka-driver.git
cd drake-franka-driver
./setup.sh

See the beginning of setup.sh for more flags.

Running the driver

Once built, the executable drake-franka-driver can be found in the build/ directory. In order to run the driver, execute:

./franka.sh

To run the driver in simulated mode without connecting to real Franka hardware, run the following:

export SIM_ROBOT=true
./franka.sh

Communicating with the robot

Sending commands to the robot from another program via LCM

The driver listens for plans encoded as a piecewise polynomial of LCM type robot_msgs::robot_spline_t on the <FRANKA_ID>_PLAN LCM channel. By default the name is FRANKA_ plus the capitalized first letter of the hostname of the computer running the drake-franka-driver. The FRANKA_ID can be overridden by setting the robot_name field in the parameters file.

Currently active plans can be paused or canceled with a robot_msgs::pause_cmd LCM message via the <FRANKA_ID>_STOP LCM channel.

If the driver is running in simulated mode, it is possible to simulate driver events like Franka control exceptions, or pressing the user stop button, on the <FRANKA_ID>_SIM_EVENT_TRIGGER LCM channel.

Listening to the robot response

The driver publishes the following LCM channels with information about the current status:

• <FRANKA_ID>_STATUS of type drake::lcmt_iiwa_status with information about joint positions, velocities, etc.
• <FRANKA_ID>_ROBOT_STATUS of type robot_msgs::robot_status_t which includes more comprehensive information that's included in the franka::RobotState struct including end effector forces
• <FRANKA_ID>_DRIVER_STATUS of type robot_msgs::driver_status_t which contains high level information about the driver, if it is currently running a plan, if it's paused or user stopped, etc.

Starting driver

In our implementation, the NUC runs this driver to talk to the Franka Controller. There are 3 ways to start the driver.

Using dexai-cli from beast machine

On the beast machine, run

dexai-cli run -c ful -v <desired_deploy_docker_version>

Note: this will bring up the entire system on the desired version, including the Franka driver and AA driver on the NUC, and the TLE container and deploy container for di/ROS services on the beast machine.

Using ./run_drivers.sh script on NUC

Open an ssh session into the NUC and do the following:

cd ~/fullstack
./run_drivers.sh --tag <desired_deploy_docker_version>
# example: ./run_drivers.sh --tag 7.1.56

Building from source

Sometimes, building from source is required in order to test a new feature in the driver. Open an ssh session into the NUC and do the following:

docker kill franka-driver-deploy # if there is currently a driver running
cd ~/dev_fullstack
git checkout <your_feature_branch>
./build_fullstack_detached.sh -b

Once the build completes, you can enter the running docker container and manually start the driver:

cd /src/drake-franka-driver
./franka.sh