Developing data hungry code, e.g. machine learning applications, comes with the burden of creating and maintaining datasets. While creating a dataset might seem to be most of the work, often enough, maintaining it is the hard part.

Example: Cycle GAN

The cycle GAN requires a set of real images captured on the real car and a set of simulated images recorded within the simulation. After training, the resulting generator is able to translate simulated images into real looking images.

However, everytime something is changed within the simulation; even something small in the background, the cycle GAN must be retrained with up to date images from the simulation.

DVC is used in combination with scripts explained in Simulated Rosbags to dramatically reduce the effort spent keeping the datasets up to date.

The principal idea is to use dvc pipelines, i.e. multiple commands with meta-information about dependencies and outputs that are defined in dvc.yaml files, to reproducibly create datasets that solely depend on the simulation. Whenever the dependencies change, the pipeline can be run again and a new version of the dataset generated.

Automatic Labeling

A key benefit of simulations is that all information about the world is available. This fact can be used automatically generate labeled data using the simulation.

First, a rosbag of the simulation running with the LabelCameraNode is recorded and in a second step, the necessary information extracted from the rosbag using scripts from Simulated Rosbags. The result is a folder of images with an additional yaml file that contains all labels. With the folder can be used as a dataset.