12. Roadmap

Roadmap

The first group of discretization approaches that you will learn is referred to by the name Roadmap. These methods represent the configuration space using a simple connected graph - similar to how a city can be represented by a metro map.

Roadmap methods are typically implemented in two phases:

  • The construction phase builds up a graph from a continuous representation of the space. This phase usually takes a significant amount of time and effort, but the resultant graph can be used for multiple queries with minimal modifications.

  • The query phase evaluates the graph to find a path from a start location to a goal location. This is done with the help of a search algorithm.

In this Discretization section, we will only discuss and evaluate the construction phase of each Roadmap method. Whereas the query phase will be discussed in more detail in the Graph Search section, following Discretization.

The two roadmap methods that you will learn next are the Visibility Graph, and Voronoi Diagram methods.