Mobile robot navigation

For any mobile device, the ability to navigate in its environment is one of the most important capabilities of all. Staying operational, i.e. avoiding dangerous situations such as collisions and staying within safe operating conditions (temperature), radiation, exposure to weather, etc.) come first, but if any tasks are to be performed that relate to specific places in the robot environment, navigation is a must. In the following, we will present an overview of the skill of navigation and try to identify the basic blocks of a robot navigation system, types of navigation systems, and closer look at its related building components.

Robot navigation means its ability to determine its own position in its frame of reference and then to plan a path towards some goal location. In order to navigate in its environment, the robot or any another mobility device requires representation i.e. a map of the environment and the ability to interpret that representation.

Navigation can be defined as the combination of the Three fundamental competences:

1. Self-Localisation
2. Path Planning
3. Map-Building and Map-Interpretation

Map in this context denotes any one-to-one mapping of the world onto an internal representation.

Robot localization denotes the robot's ability to establish its own position and orientation within the frame of reference. Path planning is effectively an extension of localisation, in that it requires the determination of the robot's current position and a position of a goal location, both within the same frame of reference or coordinates. Map building can be in the shape of a metric map or any notation describing locations in the robot frame of reference.

Vision-Based Navigation

Vision-Based Navigation uses optical sensors include laser-based range finder and photometric cameras using CCD arrays to extract the visual features required to the localization in the surrounding environment. However, there are a range of techniques for navigation and localization using vision information, the main components of each technique are:

• representations of the environment.
• sensing models.
• localization algorithms.

In order to give an overview of vision-based navigation and its techniques, we classify these techniques under indoor navigation and outdoor navigation.

Indoor Navigation

The easiest way of making a robot go to a goal location is simply to guide it to this location. This guidance can be done in different ways: burying an inductive loop or magnets in the floor, painting lines on the floor, or by placing beacons, markers, bar codes etc. in the environment. Such Automated Guided Vehicles (AGVs) are used in industrial scenarios for transportation tasks.

There are a very wider variety of indoor navigation systems. The basic reference of indoor and outdoor navigation systems is "Vision for mobile robot navigation: a survey" by Guilherme N. DeSouza and Avinash C. Kak.

Also see "Vision based positioning"

References

• Mobile Robot Navigation Jonathan Dixon, Oliver Henlich - 10 June 1997

Further reading

• BECKER, M. ; DANTAS, Carolina Meirelles ; MACEDO, Weber Perdigão, "Obstacle Avoidance Procedure for Mobile Robots". In: Paulo Eigi Miyagi; Oswaldo Horikawa; Emilia Villani. (Org.). ABCM Symposium Series in Mechatronics, Volume 2. 1 ed. São Paulo - SP: ABCM, 2006, v. 2, p. 250-257. ISBN 978-85-85769-26-0

External links

• line tracking sensors for robots and its algorithms