Decentralized approach to unmanned aerial vehicle navigation: Without the use of the global positioning system and preloaded maps

In this paper the issue of autonomous navigation is addressed, i.e. the ability for a navigation system to provide information about the states of a vehicle without the need for a priori infrastructures such as the global positioning system (GPS), beacons or preloaded maps of the area of interest. The algorithm applied is known as simultaneous localization and mapping (SLAM). It is a terrain-aided navigation system that has the capability for on-line map building, while simultaneously utilizing the generated map to bound the errors in the navigation solution. As no a priori terrain information nor initial knowledge of the vehicle location is required, this algorithm presents a powerful navigation augmentation system. More importantly, it can be implemented as an independent navigation system. This paper also describes a decentralized SLAM algorithm that allows multiple vehicles to acquire a joint three-dimensional map via a decentralized information fusion network. The key idea behind this decentralized SLAM is to represent the map in information form (negative log likelihood) for communication. Experimental results are provided using computer simulation to demonstrate the single-vehicle and multi-vehicle SLAMs without the use of GPS and preloaded maps.