Path Planners

This section explains how to use and optionally extend the path planners in pyrobosim.

PathPlanner Interface

pyrobosim uses an interface based approach to path planners.

from pyrobosim.navigation import PathPlanner
path_planner = PathPlanner(planner_type, **planner_config)

A specific planner can be selected through the planner interface, by providing the planner_type and a configuration given as **planner_config.

Each planner can potentially have multiple implementations. A specific implementation can be selected by providing the relevant parameters in **planner_config.

Available planner types and their available implementations can be found below :

Adding New Planners

The path planners in pyrobosim are designed to be extensible, so that you can add your own implementation for an existing planner type, or even a new planner type.

For example, to add a new planner type called NewPlanner:

Create the planner factory class NewPlanner which inherits pyrobosim.navigation.planner_base

from pyrobosim.navigation import PathPlannerBase

class NewPlanner(PathPlannerBase):
    pass

Create concrete implementations of your planner similar to pyrobosim.navigation.rrt.RRTPlannerPolygon

class NewPlannerPolygon:
    pass

Next, you should specify the mechanism to select the concrete implementation of your planner type in the __init__(), and implement the plan() method. Refer to pyrobosim.navigation.rrt.RRTPlanner for an example on how to do this.

from pyrobosim.navigation import PathPlannerBase

class NewPlanner(PathPlannerBase):

    def __init__():
        # do implementation selection here.

    def plan():
        # Call implementations to compute path , do any pre or post processing

Add the planner type to the list of supported planners in pyrobosim.navigation.path_planner

self.planners = {"astar": AstarPlanner, "rrt": RRTPlanner, "prm": PRMPlanner, "new_planner": NewPlanner}

Use the PathPlanner interface to use your new planner.

new_path_planner  = PathPlanner("new_planner", **planner_config)

Note

Planner implementations that need to display graphs should provide a get_graphs() method and set the graphs attribute of PathPlannerBase like in pyrobosim.navigation.rrt.RRTPlannerPolygon.get_graphs() and pyrobosim.navigation.rrt.RRTPlanner.plan().