Residual Policy Learning for Vehicle Control of Autonomous Racing Cars

This repository is the official implementation of the paper:

Residual Policy Learning for Vehicle Control of Autonomous Racing Cars

Trumpp, Raphael, Denis Hoornaert, and Marco Caccamo.

The paper will be presented at the IEEE Intelligent Vehicle Symposium 2023. If you find our work useful, please consider citing it.

Table of contents

• Background
• Install
• Usage
• Reference
• License

Background

The development of vehicle controllers for autonomous racing is challenging because racing cars operate at their physical driving limit. Prompted by the demand for improved performance, autonomous racing research has seen the proliferation of machine learning-based controllers. While these approaches show competitive performance, their practical applicability is often limited. Residual policy learning promises to mitigate this by combining classical controllers with learned residual controllers. The critical advantage of residual controllers is their high adaptability parallel to the classical controller's stable behavior. We propose a residual vehicle controller for autonomous racing cars that learns to amend a classical controller for the path-following of racing lines. In an extensive study, performance gains of our approach are evaluated for a simulated car of the F1TENTH autonomous racing series. The evaluation for twelve replicated real-world racetracks shows that the residual controller reduces lap times by an average of 4.55 % compared to a classical controller and zero-shot generalizes to new racetracks.

Residual Policy Learning

Proposed control architecture consisting of a base controller that outputs control action $a_{\text{B}}$ which is added to the residual action $a_{\text{R}}$ to form the combined action $a_{\text{RB}}$. The action $a_{\text{R}}$ of the residual controller is sampled from a distribution whose parameters are defined by a NN.

Simulator and Racetracks

This repository uses an adapted version of the F1TENTH gym as simulator. Map data of replicated real-world racetracks are used from the F1TENTH maps repository.

Racetracks for training and testing: (a) Nurburgring, (b) Moscow Raceway, (c) Mexico City, (d) Brands Hatch, (e) Sao Paulo, (f) Sepang, (g) Hockenheim, (h) Budapest, (i) Spielberg, (j) Sakhir, (k) Catalunya, and (l) Melbourne.

Results: Lap times

Training:

Track	Baseline in s	Residual in s	Improvement in s	Improvement in %
Nuerburgring	60.84	58.07	2.77	4.55
Moscow	46.75	43.45	3.30	7.06
Mexico City	49.12	46.76	2.36	4.80
Brands Hatch	45.92	44.97	0.95	2.07
Sao Paulo	47.92	44.92	3.00	6.26
Sepang	66.24	63.18	3.06	4.62
Hockenheim	49.96	47.35	2.61	5.22
Budapest	54.33	51.67	2.66	4.90
Spielberg	45.33	43.93	1.40	3.09

Test:

Track	Baseline in s	Residual in s	Improvement in s	Improvement in %
Sakhir	60.34	57.72	2.62	4.34
Catalunya	56.50	53.54	1.49	5.24
Melbourne	61.03	59.54	2.96	2.44

Overall:

Track	Baseline in s	Residual in s	Improvement in s	Improvement in %
Average	53.69	50.85	2.43	4.55

Install

• We recommend to use a virtual environment for the installation:

  python -m venv rpl4f110_env
  source rpl4f110_env/bin/activate

• Activate the environment and install the following packages:

  pip install torch
  pip install gymnasium
  pip install tensorboard
  pip install hydra-core
  pip install tqdm
  pip install flatdict
  pip install torchinfo
  pip install torchrl
  pip install numba
  pip install scipy
  pip install pyglet
  pip install pillow
  pip install pyglet==1.5

• The simulator should be installed as a module:

  cd simulator
  pip install -e .

Usage

Training

After setting you desired configuration in the config.yaml file, you can start the training by running:

python main.py

Specific names of the experiment can be set by running:

python main.py +exp_name=your_experiment_name

The use of your GPU can be avoided by running:

python main.py +cuda=False

Monitoring

The training results are stored in the outputs folder. The training progress can be monitored with tensorboard:

tensorboard --logdir outputs

Others

The baseline controller can be evaluated by running:

python main.py +bench_baseline=True

Docstrings

Most of the code is documented with automatically generated docstrings, please use them with caution.

Reference

If you find our work useful, please consider citing our paper:

@inproceedings{trumpp2023residual,
author="Raphael Trumpp and Denis Hoornaert and Marco Caccamo",
title="Residual Policy Learning for Vehicle Control of Autonomous Racing Cars",
booktitle="2023 IEEE Intelligent Vehicles Symposium (IV) (IEEE IV 2023)",
address="Anchorage, USA",
days="4",
moth=jun,
year=2023,
keywords="Residual Policy Learning; Autonomous Racing; Vehicle Control; F1TENTH"
}

License

GNU General Public License v3.0 only" (GPL-3.0) © raphajaner