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 serl
   pip install -e .

Usage

Robot Server

To start using the robot, first power on the robot (small switch on the back of robot control box on the floor). Unlock the robot from the browser interface by going to robot IP address in your browser, then press the black and white button to put the robot in FCI control mode (blue light).

From there you should be able to navigate to serl_robot_infra and then simply run the franka server. This requires to be in a ROS environment.

conda activate serl

# Script to start http server and ros controller
python serl_robot_infra/robot_servers/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>

# Activate the gripper after running the franka_server if you are using a Robotiq gripper
curl -X POST http://127.0.0.1:5000/activate_gripper

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	Stop the impedance controller
stopimp	Start 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+quaternion)
getpos_euler	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). This needs to be run after starting franka_server to control the Robotiq gripper.
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 http://127.0.0.1:5000/activate_gripper # Activate gripper
curl -X POST http://127.0.0.1:5000/close_gripper # Close gripper
curl -X POST http://127.0.0.1:5000/open_gripper # Open gripper
curl -X POST http://127.0.0.1:5000/getpos_euler # Print current end-effector pose
curl -X POST http://127.0.0.1:5000/jointreset # Perform joint reset
curl -X POST http://127.0.0.1:5000/stopimp # Stop the impedance controller
curl -X POST http://127.0.0.1:5000/startimp # Start the impedance controller (**Only run this after stopimp**)

Robot Env (Client)

Lastly, we use a gym env interface to interact with the robot server, defined in this repo under franka_env. Simply run pip install -e . in the robot_infra directory, and in your code simply initialize the env via gym.make("Franka-{ENVIRONMENT NAME}-v0).

Example Usage

import gym
import franka_env
env = gym.make("FrankaEnv-Vision-v0")

Provided Environments

1. peg insertion
2. pcb insertion
3. cable routing
4. bin relocation

Please refer to their respective examples in serl/examples/ directory.