serl_robot_infra

SERL Robot Infra

All robot code is structured as follows: There is a Flask server which sends commands to the robot via ROS. There is a gym env for the robot which communicates with the Flask server via post requests.

• robot_server: hosts a Flask server which sends commands to the robot via ROS
• franka_env: gym env for the robot which communicates with the Flask server via post requests

Installation

1. Install libfranka and franka_ros with instructions here.

2. Then install the serl_franka_controllers from https://github.com/rail-berkeley/serl_franka_controllers

3. Then, install this package and it's dependencies.

   conda activate hilserl
   pip install -e .

Usage

To start using the robot, first power on the robot (small switch on the back of robot control box on the floor). Calibrate the end-effector payload in the browser interface before proceeding to ensure accuarcy of the impedance controller. Then, unlock the robot, enable FCI, and put into execution mode (FR3 only).

The following command are used to start the impedance controller and robot server that the gym environment communicates with. For bimmanual setup, you can run completely independent servers for each arm even if they have different firmware version (we have a Panda and a FR3) by using different catkin_ws, ROS_MASTER_URI, and flask_url. We have provided examples at launch_left_server.sh and launch_right_server.sh

cd robot_servers
conda activate hilserl

# source the catkin_ws that contains the serl_franka_controllers package
source </path/to/catkin_ws>/devel/setup.bash

# Set ROS master URI to localhost
export ROS_MASTER_URI=http://localhost:<ros_port_number>

# script to start http server and ros controller
python franka_server.py \
    --gripper_type=<Robotiq|Franka|None> \
    --robot_ip=<robot_IP> \
    --gripper_ip=<[Optional] Robotiq_gripper_IP> \
    --reset_joint_target=<[Optional] robot_joints_when_robot_resets> \
    --flask_url=<url_to_serve> \
    --ros_port=<ros_port_number> \

This should start ROS node impedence controller and the HTTP server. You can test that things are running by trying to move the end effector around, if the impedence controller is running it should be compliant.

The HTTP server is used to communicate between the ROS controller and gym environments. Possible HTTP requests include:

Request	Description
startimp	Start the impedance controller
stopimp	Stop the impedance controller
pose	Command robot to go to desired end-effector pose given in base frame (xyz+quaternion)
getpos	Return current end-effector pose in robot base frame (xyz+rpy)
getvel	Return current end-effector velocity in robot base frame
getforce	Return estimated force on end-effector in stiffness frame
gettorque	Return estimated torque on end-effector in stiffness frame
getq	Return current joint position
getdq	Return current joint velocity
getjacobian	Return current zero-jacobian
getstate	Return all robot states
jointreset	Perform joint reset
activate_gripper	Activate the gripper (Robotiq only)
reset_gripper	Reset the gripper (Robotiq only)
get_gripper	Return current gripper position
close_gripper	Close the gripper completely
open_gripper	Open the gripper completely
move_gripper	Move the gripper to a given position
clearerr	Clear errors
update_param	Update the impedance controller parameters

These commands can also be called in terminal. Useful ones include:

curl -X POST <flask_url>:5000/activate_gripper # Activate gripper
curl -X POST <flask_url>:5000/close_gripper # Close gripper
curl -X POST <flask_url>:5000/open_gripper # Open gripper
curl -X POST <flask_url>:5000/getpos # Print current end-effector pose in xyz translation and xyzw quaternions
curl -X POST <flask_url>:5000/getpos_euler # Get current end-effector pose in xyz translation and xyz euler angles
curl -X POST <flask_url>:5000/jointreset # Perform joint reset
curl -X POST <flask_url>:5000/stopimp # Stop the impedance controller
curl -X POST <flask_url>:5000/startimp # Start the impedance controller (**Only run this after stopimp**)

Egg Flip Controller

This is only a very naive wrench based controller that we implemented for the egg flip task specifically. We are release it only for reference and those really interested in seeing how we did the dynamic tasks.

DISCLAIMER: DO NOT use this unless you know what you are doing and accept the risk of damaging the robot. However, if you do decide to run this, make sure there is clear space in front, below, and above the robot as launching the server will cause the robot to move into the reset position.

Installation

1. Complete all of the steps above to install serl_robot_controllers.
2. Copy the egg_flip_controller directory into your catkin_ws/src directory.
3. Build this pacakge

   catkin_make --pkg egg_flip_controller

4. Launch the egg flip server

   cd robot_servers
   conda activate hilserl
   
   # source the catkin_ws that contains the serl_franka_controllers package
   source </path/to/catkin_ws>/devel/setup.bash
   
   # Set ROS master URI to localhost
   export ROS_MASTER_URI=http://localhost:<ros_port_number>
   
   # script to start http server and ros controller
   python franka_server.py \
       --gripper_type=None \
       --robot_ip=<robot_IP> \
       --flask_url=<url_to_serve> \
       --ros_port=<ros_port_number> \