DEX: Demonstration-Guided RL with Efficient Exploration for Task Automation of Surgical Robot

This is the official PyTorch implementation of the paper "Demonstration-Guided Reinforcement Learning with Efficient Exploration for Task Automation of Surgical Robot" (ICRA 2023).

Prerequisites

• Ubuntu 18.04
• Python 3.7+

Installation Instructions

1. Clone this repository.

git clone --recursive https://github.com/med-air/DEX.git
cd DEX

2. Create a virtual environment

conda create -n dex python=3.8
conda activate dex

3. Install packages

pip3 install -e SurRoL/	# install surrol environments
pip3 install -r requirements.txt
pip3 install -e .

4. Then add one line of code at the top of gym/gym/envs/__init__.py to register SurRoL tasks:

# directory: anaconda3/envs/dex/lib/python3.8/site-packages/
import surrol.gym

Usage

Commands for DEX and all baselines. Results will be logged to WandB. Before running the commands below, please change the wandb entity in train.yaml to match your account.

We collect demonstration data via the scripted controllers provided by SurRoL. Take the NeedlePick task as example:

mkdir SurRoL/surrol/data/demo
python SurRoL/surrol/data/data_generation.py --env NeedlePick-v0 

Training Commands

• Train DEX:

python3 train.py task=NeedlePick-v0 agent=dex use_wb=True

• Train SAC:

python3 train.py task=NeedlePick-v0 agent=sac use_wb=True

• Train DDPG:

python3 train.py task=NeedlePick-v0 agent=ddpg use_wb=True

• Train DDPGBC:

python3 train.py task=NeedlePick-v0 agent=ddpgbc use_wb=True

• Train CoL:

python3 train.py task=NeedlePick-v0 agent=col use_wb=True

• Train AMP:

python3 train.py task=NeedlePick-v0 agent=amp use_wb=True

• Train AWAC:

python3 train.py task=NeedlePick-v0 agent=awac use_wb=True

• Train SQIL:

python3 train.py task=NeedlePick-v0 agent=sqil use_wb=True

Again, all commands can be run on other surgical tasks by replacing NeedlePick with the respective environment in the commands (for both demo collection and RL training).

We also implement synchronous parallelization of RL training, e.g., launch 4 parallel training processes:

mpirun -np 4 python -m train agent=dex task=NeedlePick-v0 use_wb=True

It should be noted that parallel training will lead to inconsistent performance, which require hyperparameters tuning.

Evaluation Commands

We also provide a script for evaluate the saved model. The directory of the to-be-evaluated model should be included in the configuration file eval.yaml, where the checkpoint is specified by ckpt_episode. For instance:

• Eval model trained by DEX in NeedlePick-v0:

python3 eval.py task=NeedlePick-v0 agent=dex ckpt_episode=latest

Starting to Modify the Code

Modifying the hyperparameters

The default hyperparameters are defined in dex/configs, where train.yaml defines the experiment settings and YAML file in the directory agent defines the hyperparameters of each method. Modifications to these parameters can be directly defined in the experiment or agent config files, or passed through the terminal command. For example:

python3 train.py task=NeedleRegrasp-v0 agent=dex use_wb=True batch_size=256 agent.aux_weight=10

Adding a new RL algorithm

The core RL algorithms are implemented within the BaseAgent class. For adding a new algorithm, a new file needs to be created in dex/agents and BaseAgent needs to be subclassed. In particular, any required networks (actor, critic etc) need to be constructed and the update(...) function and get_action(...) needs to be overwritten. For an example, see the DDPGBC implementation in DDPGBC. When implementation is done, a registration is needed in factory.py and a config file should also be made in agent to specify the model parameters.

Transfering to other simulation platform

Our code is designed for standard goal-conditioned gym-based environments and can be easily transfered to other platform if provide the same interfaces (e.g., OpenAI gym fetch). If no similar interface is provided, some modifications should be made to make it compatible, e.g., replay buffer and sampling utilities. We will make our code more generalizable in the future.

Code Navigation

dex
  |- agents                # implements core algorithms in agent classes
  |- components            # reusable infrastructure for model training
  |    |- checkpointer.py  # handles saving + loading of model checkpoints
  |    |- normalizer.py    # normalizer for vectorized input
  |    |- logger.py        # implements core logging functionality using wandB
  |
  |- configs               # experiment configs 
  |    |- train.yaml       # configs for rl training
  |    |- eval.yaml        # configs for rl evaluation
  |    |- agent            # configs for each algorithm (dex, ddpg, ddpgbc, etc.)
  |
  |- modules               # reusable architecture components
  |    |- critic.py        # basic critic implementations (eg MLP-based critic)
  |    |- distributions.py # pytorch distribution utils for density model
  |    |- policy.py    	   # basic actor implementations
  |    |- replay_buffer.py # her replay buffer with future sampling strategy
  |    |- sampler.py       # rollout sampler for collecting experience
  |    |- subnetworks.py   # basic networks
  |
  |- trainers              # main model training script, builds all components + runs training loop and logging
  |
  |- utils                 # general and rl utilities, pytorch / visualization utilities etc
  |- train.py              # experiment launcher
  |- eval.py               # evaluation launcher

Contact

For any questions, please feel free to email taou.cs13@gmail.com.