Circle Sector Expansions for On-Line Exploration

A novel and effective method denoted circle sector expansion (CSE) is presented that can be used to generate reduced Voronoi diagrams. It is intuitive and can be used to efficiently compute possible paths for a vehicle. The idea is to model free space instead of the features in the environment. It is easy to implement and can be used while a vehicle moves and collects new data of its surrounding. The method is directly applicable and has properties for fast computations of safety margins while at the same time having low complexity. We have successfully implemented the algorithm and its methods and performed real-life tests using an autonomous wheelchair equipped with a range scanning laser, a rate gyro, and wheel-encoders. Tests showed good results for supporting the use of CSE. The results are applicable for example to improve assistive technology for wheelchair users.