We implemented Yeap’s computational theory of cognitive mapping [1], [2] on a mobile robot equipped only with sonar sensors and an odometer. As expected, the resulting maps are erroneous. We demonstrate how a network of such highly unreliable descriptions can be used to find one’s way in one’s environment. The answer lies in the use of powerful commonsense reasoning to interpret the “erroneous”...

In radar and sonar signal processing it is of interest to achieve accurate estimation of signal characteristics. Recorded pulse data have uncertainties due to emitter and receiver noise, and due to digital sampling and quantization in the receiver system. It is therefore important to quantify these effects through theory and experiment in order to construct “smart” pulse processing algorithms w...

Information obtained by the ultrasonic sensor is influenced by the characteristics of the sensing system such as sensitivity, directivity and so on. In order to investigate its influence, we constructed two ultrasonic ranging systems of which characteristics differs from each other and examined their performance such as obstacle detectability and resultant sonar map.

We describe the development of a robust map acquisition method for mobile robots in indoor environments. A grid-based representation of the environment is derived from sonar sensor data, and, concurrently, corners and edges are detected and matched with visual landmarks in order to correct the robot pose estimation. We present experimental results of maps acquired using the ApriAlphaTM home robot.

In this paper a novelty filter is introduced which allows a robot operating in an unstructured environment to produce a self-organised model of its surroundings and to detect deviations from the learned model. The environment is perceived using the robot’s 16 sonar sensors. The algorithm produces a novelty measure for each sensor scan relative to the model it has learned. This means that it hig...

Partial sightedness is a sensory disability which can to some extent be alleviated by artificial aids. Many of the sensory methods used in robotics can be applied in attempts to recapture some of the sensory information a partially sighted person has lost. This paper describes a device which uses sonar and stereo vision sensors for this task. The device is portable, and is worn by the user, giv...

This paper presents methods for navigating and localizing mobile robots in a known indoor environment. We introduce a restricted visibility concept called a scannable sector that can aid many existing navigation and localization algorithms. The scannable sectors are based on the physical characteristics of the environment and the limitations of the localization sensors used. We describe a compl...

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 classiication scheme is probabilistic and is based on empirical data: the con-dence of...

In this paper we describe a new technique for the creation of featurebased stochastic maps using standard Polaroid sonar sensors. The fundamental contributions of our proposal are: (1) a perceptual grouping process that permits the robust identification and localization of environmental features, such as straight segments and corners, from the sparse and noisy sonar data; (2) a map joining tech...