In this paper we present a complete control architecture for a mobile robot which enables it to achieve a set of proposed goals with a high degree of autonomy and to react to the changing environment in real time. Autonomy and robustness are achieved through careful selection and incremental implementation of a set of basic Motor-Behaviors that interpret the sensor readings (sonar, vision and o...

This paper addresses the problem of mapping the structure of a gas distribution by creating concentration gridmaps from the data collected by a mobile robot equipped with gas sensors. By contrast to metric gridmaps extracted from sonar or laser range scans, a single measurement from a gas sensor provides information about a comparatively small area. To overcome this problem, a mapping technique...

This article describes an algorithm for detection of obstacles, through the use of low cost sonar sensors, for the navigation of mobile robots. The use of a grid representation for the cartesian space, associated to probabilistic operations on it, allowed the implementation of a fast, simple and robust algorithm for obstacle detection. This algorithm runs always that the mobile robot navigates,...

A robot can explore an unknown environment by incrementally constructing a roadmap of that environment using line of sight sensor information. Recall that a roadmap is a one-dimensional representation of a robot's environment. This paper addresses one problem that occurs while generating a roadmap: what happens when sonar sensors cannot detect sharp objects because of the specularities? To do t...

This paper presents a reactive/local level of an Obstacle Avoidance System for an Autonomous Underwater Vehicle (AUV). The specific requirements of the underwater world, the computational capacity and the sensors of the vehicle as well as its manoeuvrability were considered by the choice and the development of strategies used. Such requirements include the sea current information, the considera...

An expert system can process active sonar returns, perform geometric analysis and autonomously classify detected underwater objects. Autonomous classification of objects is an essential requirement for independent operation by autonomous underwater vehicles (AUVs). Most AUVs are only capable of rudimentary sensor analysis, since standard approaches to evaluation and classification of sonar data...

This paper addresses the coupled tasks of constructing a spatial representation of the environment with a mobile robot using noisy sensors (sonar) and using such a map to determine the robot's position. The map is not meant to represent the actual spatial structure of the environment so much as it is meant to represent the major structural components of what the robot \sees". This can, in turn,...

A novel method is described for surface profile extraction based on morphological processing of multiple range sensor data. The approach taken is extremely flexible and robust, in addition to being simple and straightforward. It can deal with arbitrary numbers and configurations of range sensors as well as synthetic arrays obtained by moving a relatively small number of sensors. The method has ...

Currently, the viability of infrared (IR) as an accurate means of measuring distance depends on extensive prior knowledge of the surface. More speci cally, the manner in which a surface scatters, re ects, and absorbs infrared energy is needed to interpret the sensor output as a distance measure. In order to use IR in an unknown environment, one must determine the surface properties during robot...

In this paper, we are interested in inferring the sources of various types of sonar features typically observed by a mobile robot. After a brief discussion of terrestrial sonar sensing, we develop a set of operators that associates arc-shaped features extracted from sonar scans with real world primitives. Our classi cation scheme is probabilistic and is based on empirical data: the condence of ...