[NeurIPS 2023] Active Observing in Continuous-time Control

This repo holds the code, and log files for Active Observing in Continuous-time Control by Samuel Holt, Alihan Hüyük, and Mihaela van der Schaar.

Introduction

For the first time, we introduce and formalize the problem of continuous-time control with costly observations, theoretically demonstrating that irregular observation policies outperform regular ones in certain environments. We empirically validate this finding using a novel initial method: applying a heuristic threshold to the variance of reward rollouts in an offline continuous-time model-based Model Predictive Control (MPC) planner across various continuous-time environments, including a cancer simulation. This work lays the foundation for future research on this critical problem.

Setup

To get started:

1. Clone this repo

git clone https://github.com/samholt/ActiveObservingInContinuous-timeControl && cd ./ActiveObservingInContinuous-timeControl

2. Follow the installation instructions in setup/install.sh to install the required packages.

./setup/install.sh

Replicating the main results

To replicate the main results, run the following commands:

python mppi_with_model_active_observing.py

Once the run has completed, process the log file generated output into the logs folder, with the script process_results/analyzer.py. Note, you will need to edit the process_result_file.py to read this generated log file, i.e., specify the path variable of where it is. This will generate the main tables as presented in the paper.

Retraining the dynamics models from scratch

1. Modify the configuration dictionary in file config.py.
2. You can either re-train an individual model, or all the models together using multiprocessing. 2.a To re-train a single model, modify the settings (i.e. the model_name and train_env_task) of train_utils.py and run python train_utils.py. 2.b To re-train all the models together, run python train_all_models.py. 2.c Note, when re-training a model, it should be trained until it converges. A good rule is after three days per model with a NVIDIA RTX 3090 (adapt accordingly based on your available GPU or compute).
3. For any newly trained model, you will now have to tune a new threshold parameter as described in the paper, by running it using the mppi_with_model_active_observing.py script. Specifically running with the method of continuous_planning for a pe model or discrete_planning for a pe-discrete model. You will have uncomment the line print(f"THRESHOLD: {df.mean()['costs_std_median']}") and turn on debug mode and plot_telem in the config. This will print out the threshold value to use for the model. You will then have to update the config.py file with this new threshold value for your model.
4. To re-run with the newly trained models, continue with the same replicating the main results instructions above.

Cite

If you use our work in your research, please cite:

@inproceedings{
    holt2023active,
    title={Active Observing in Continuous-time Control},
    author={Samuel Holt and Alihan H{\"u}y{\"u}k and Mihaela van der Schaar},
    booktitle={Thirty-seventh Conference on Neural Information Processing Systems},
    year={2023},
    url={https://openreview.net/forum?id=o0ggjFD24U}
}