Implement custom planner

[AlessandroCapobianco]

I would like to integrate my customized planner into Open-RMF, my idea is to replace the a_star_search function with my own custom function here here.

I noticed that, although a_star_search returns the position for each node of node_sequence, it is not decisive because even if my planner returns (0,0) as position the simulation continues correctly, a sign that some function upstream of a_star_search is able to recalculate correctly the position.

However, I have difficulty managing time. I would like to know how to correctly populate the time field of each node so that it is consistent with the node_sequence returned by my planner.

[mxgrey]

The current generation of Open-RMF was not designed with the intention of the traffic planner being replaced or modified. You're perfectly allowed to do it per the rights granted by the BSD license, but I would urge you to reconsider because you will find it prohibitively difficult at both the software engineering level and at the algorithmic level. It's very difficult to write an efficient and effective motion planner that can account for moving obstacles in the world.

If you can let me know what you need out of the planner which it doesn't currently provide I may be able to offer an alternative that's more suitable to your needs than modifying the planner implementation. If you need something that cannot be achieved by the current planner, then I can take those needs into account as we roll out the next generation traffic planner.