Does Cooperative A* work?

[yjkim046]

Describe the bug
WWWWWWWWWWWWWWWWWWWW
WW___________________WWWWWW
W_A___B____________goalB_goalA_W
WWWWWWWWWWWWWWWWWWWW

Robot A can't find its path in the scenario above.

To Reproduce
Steps to reproduce the behavior:

1. Set the wall and A,B in the above
2. Run simulation

Expected behavior
A and B finds its path, respectively.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Ubuntu 20.04
• Browser Chrome

Additional context
I see "WARNING Path not found for agent [A]" in the terminal.

[guilyx]

Hi there,

There's some significant work to be done on Cooperative A*. This situation is one of them. If you switch B and A it will work. I'll see what I can do but I think it might just be re-running an A* on the agents that failed to find a path after computing other's paths. Eitherway, I'll soon get going on Enhanced Conflict Based Search (ECBS) that will be significantly better than CA*, which to be honest I don't like at all.

[guilyx]

Hi again @yjkim046, can you share the snippet of code for initialization of the World/Agents so I can reproduce the same sequence ?

[sampreets3]

Hi @yjkim046, from a first look at the problem it seems as if it is failing because there arises a case of "collision" during the plan. In the sense that once robot B has found the goal, it is acting like an obstacle for robot A's plan. I am not entirely sure if this is the exact cause of the problem, but maybe you can provide us with either the log or the application code for the bug to reproducable, as @guilyx said.