Python version

Our code is tested with Python >= 3.5.2

List of components

• helper_funcs_glob: This python module contains some helper functions used in several other functions when calculating the global race trajectory.
• inputs: This folder contains the ggv diagrams and reference track csvs for the global race trajectory.
• int_globalenv_trajgen: This python module contains a function to import the track csvs in the inputs folder.
• opt_geometrical: This python module contains the optimization functions required to find either the minimum curvature path or the shortest path.
• opt_mintime: This python module contains the functions required to find the minimum time trajectory for a point-mass-model (PM), a one-track-model (ESM) and a two-track-model (ZSM).
• outputs: The calculated race trajectory informations are exported to various csvs in this folder.
• params: This folder contains the vehicle dependent parameter files.
• process_functions: This folder contains scripts to reduce the code contained in the main_globtraj.py.

Dependencies

Use the provided requirements.txt in the root directory of this repo, in order to install all required modules.
pip3 install -r /path/to/requirements.txt

Running the code

• Step 1: (optional) Adjust the parameter file that can be found in the params folder.
• Step 2: (optional) Adjust the ggv diagram file in inputs/ggv.
• Step 3: (optional) Add your own reference track file in inputs/tracks.
• Step 4: Check the parameters in the upper part of main_globaltraj.py and execute it to start the trajectory generation process.

Wording and conventions

We tried to keep a consistant wording for the variable names:

path -> [x, y] Describes an array containing points (i.e. point coordinates).
refline -> [x, y] A path that is used as reference line during our calculations.
reftrack -> [x, y, w_tr_right, w_tr_left] An array that contains not only the reference line information but also right and left track widths. In our case it contains the race track that is used as a basis for the raceline optimization.

Normal vectors usually point to the right in the direction of driving. Therefore, we get the track boundaries by multiplication as follows: norm_vector * w_tr_right, -norm_vector * w_tr_left.

Trajectory interface definition

The output csv contains the global race trajectory. The array is of size [no_points x 7] where no_points depends on stepsize and track length. The seven columns are structured as follows:

• s_m: float32, meter. Curvi-linear distance along the raceline.
• x_m: float32, meter. X-coordinate of raceline point.
• y_m: float32, meter. Y-coordinate of raceline point.
• psi_rad: float32, rad. Heading of raceline in current point from -pi to +pi rad. Zero is north (along y-axis).
• kappa_radpm: float32, rad/meter. Curvature of raceline in current point.
• vx_mps: float32, meter/second. Target velocity in current point.
• ax_mps2: float32, meter/second². Target acceleration in current point.

Detailed description of the curvature minimization used during trajectory generation

Please refer to our paper for further information:
Heilmeier, Wischnewski, Hermansdorfer, Betz, Lienkamp, Lohmann
Minimum Curvature Trajectory Planning and Control for an Autonomous Racecar
DOI: 10.1080/00423114.2019.1631455

Contact person: Alexander Heilmeier.