Space-Time AStar

[SchwartzCode]

Reference issue

What does this implement/fix?

This implements SpaceTime A* as outlined in this paper:
https://www.davidsilver.uk/wp-content/uploads/2020/03/coop-path-AIWisdom.pdf

This is a variant of A* that works with dynamic obstacles. I wanted to implement this to serve as a baseline before implementing Safe Interval Path Planning, which is a clever path planning algorithm that greatly reduces the number of node expansions in problems with dynamic obstacles.

Some examples of the SpaceTime A* algorithm running:

Additional information

CheckList

• Did you add an unittest for your new example or defect fix?
• Did you add documents for your new example?
• All CIs are green? (You can check it after submitting)

[SchwartzCode]

I didn't find a home for path planning algorithms with dynamic obstacles, let me know if there is somewhere better for this to live :)

I used ruff format to format these files, is there something else I should use?

I also didn't look at all of the CI jobs - will come back to address those tomorrow (it's time for sleep where I'm at)

[AtsushiSakai]

@SchwartzCode Thank you for great PR!! I loved it.

let me know if there is somewhere better for this to live :)

Creating a new directory under here:
https://github.com/AtsushiSakai/PythonRobotics/tree/master/PathPlanning
is fine for me.

I used ruff format to format these files, is there something else I should use?

I think it is enough, but please check all CIs are green.

I also didn't look at all of the CI jobs - will come back to address those tomorrow (it's time for sleep where I'm at)

I think all CIs are running, but some are failed,

[SchwartzCode]

@AtsushiSakai Glad you like the PR! I fixed the CI

[AtsushiSakai]

Thank you. @SchwartzCode I have 2 additional requests.

1
Could you please create a PR to add the gifs for this repository?
https://github.com/AtsushiSakai/PythonRoboticsGifs

2
Is it possible to add documentation for this new script based on the manual?
https://atsushisakai.github.io/PythonRobotics/modules/0_getting_started/3_how_to_contribute.html#step-4-write-a-document-about-the-algorithm

[SchwartzCode]

PR into the gifs repo: AtsushiSakai/PythonRoboticsGifs#6

[SchwartzCode]

Added a short doc entry here: 451e545

[AtsushiSakai]

Thank you. I have additional comments and questions. PTAL,

[AtsushiSakai]

Thank you!!. @SchwartzCode After, all CIs are green, I will merge this.