This paper addresses the problem of mapping the features of a gas distribution by creating concentration gridmaps with a mobile robot equipped with a gas-sensitive system (“mobile nose”). By contrast to metric gridmaps extracted from sonar or laser range scans, a gas sensor measurement provides information about a comparatively small area. To overcome this problem, a mapping technique is introd...

In this paper, we show how linguistic expressions can be generated to describe the spatial relations between a mobile robot and its environment, using readings from a ring of sonar sensors. Our work is motivated by the study of human-robot communication for non-expert users. The eventual goal is to use these linguistic expressions for navigation of the mobile robot in an unknown environment, wh...

for range-independent resolution—was thought to be untenable due to lack of coherence in the ocean medium, precise platform navigation requirements and burdensome computation rates. With advances in innovative motion-compensation and auto-focusing techniques, signal-processing hardware, affordable and precise navigation sensors, and stable submerged autonomous platforms, synthetic aperture sona...

Passive acoustic data collected from marine autonomous recording units deployed off Jacksonville, FL (from 13 September to 8 October 2009 and 3 December 2009 to 8 January 2010), were analyzed for detection of cetaceans and Navy sonar. Cetaceans detected included Balaenoptera acutorostrata, Eubalaena glacialis, B. borealis, Physeter macrocephalus, blackfish, and delphinids. E. glacialis were det...

This paper addresses a practical problem arising in the calibration of bottom-lock doppler sonar for the navigation of underwater robot vehicles. Employing a least-squares method, the rotational alignment offset between a bottom-lock doppler sonar and a north-seeking gyroscope can be experimentally determinined using sensors commonly deployed with a vehicle in the field. It requires sensor valu...

a direct impact on the information available to its acoustic imaging system. In turn, the bat’s perception of the echo scene guides its adjustments of the features of subsequent sonar vocalizations. Therefore, the bat’s adaptive sonar behavior can shed light on the fundamental processes that underlie auditory scene analysis by echolocation. Indeed, the bat’s active sonar behavior allows us to l...

A substantial challenge in robotics is integration of complex software systems for realtime performance. This thesis integrates the robust and generic mapping framework Atlas, a feature-based local Simultaneous Localization and Mapping (SLAM) module, and obstacle avoidance using information from mapped features. The resulting system performs autonomous feature-relative Real-time Obstacle Avoida...

Building occupancy grid maps with sonar sensors is a challenging task due to angular uncertainty, specular reflections and crosstalk. This paper presents a quantitative comparison of two probabilistic and one heuristic approaches to the robotic mapping using real sonar data – inverse and forward sensor models and the CEMAL methods. Moreover, the two probabilistic methods are also tested pre-fil...

The control of underwater robots presents a number of unique and formidable challenges. Underwater robot dynamics are highly nonlinear, coupled, and timevarying, and subject to hydrodynamic uncertainties and external disturbances such as current. Unlike land mobile robots, underwater robots cannot use GPS (Global Positioning System). Most popular underwater positioning sensors are sonar-based, ...