This paper addresses problems of inferring the locations of moving agents from combinatorial data extracted by robots that carry sensors. The agents move unpredictably and may be fully distinguishable, partially distinguishable, or completely indistinguishable. The key is to introduce information spaces that extract and maintain combinatorial sensing information. This leads to monitoring the changes in connected components of the shadow region, which is the set of points not visible to any sensors at a given time. When used in combination with a path generator for the robots, the approach solves problems such as counting the number of agents, determining movements of teams of agents, and solving pursuit-evasion problems. An implementation with examples is presented.

Abstract — In this paper, we present a real-time algorithm for online simultaneous localization and mapping (SLAM) with detection and tracking of moving objects (DATMO) in dynamic outdoor environments from a moving vehicle equipped with laser sensor and odometry. To correct vehicle location from odometry we introduce a new fast implementation of incremental scan matching method that can work reliably in dynamic outdoor environments. After a good vehicle location is estimated, the surrounding map is updated incrementally and moving objects are detected without a priori knowledge of the targets. Detected moving objects are finally tracked using Global Nearest Neighborhood (GNN) method. The experimental results on datasets collected from different scenarios such as: urban streets, country roads and highways demonstrate the efficiency of the proposed algorithm. I.

www.elsevier.com/locate/robot This paper presents Scan-SLAM, a new generalization of simultaneous localization and mapping (SLAM). SLAM implementations based on extended Kalman filter (EKF) data fusion have traditionally relied on simple geometric models for defining landmarks. This limits EKF-SLAM to environments suited to such models and tends to discard much potentially useful data. The approach presented in this paper is a marriage of EKF-SLAM and scan correlation. Landmarks are no longer defined by analytical models; instead they are defined by templates composed of raw sensed data. These templates can be augmented as more data become available so that the landmark definition improves with time. A new generic observation model is derived that is generated by scan correlation, and this permits stochastic location estimation for landmarks with arbitrary shape within the Kalman filter framework. The statistical advantages of an EKF representation are augmented with the general applicability of scan matching. Scan matching also serves to enhance data association reliability by providing a shape metric for landmark disambiguation. Experimental results in an outdoor environment are presented which validate the algorithm. c ○ 2006 Elsevier B.V. All rights reserved. Keywords: Simultaneous localisation and mapping (SLAM); EKF-SLAM; Scan correlation

Accomplishing simultaneous localization and mapping (SLAM) in very large city environments is a great challenge because of theoretical and practical issues on computational complexity, dynamic environment, representation and data association. In this paper, we describe practical algorithms for dealing with the representation issues. Featurebased, grid-based and direct methods are integrated into the framework of the hierarchical object based representation. The sampling and correlation based range image matching algorithm is developed to tackle the problem arising from uncertain, sparse and featureless data in outdoor environments. Experimental results of a 800 meter x 600 meter neighborhood demonstrate the feasibility of city-sized SLAM.

Abstract—The approach investigated in this work employs LADAR measurements to detect and track pedestrians over time. The algorithm can process range measurements from both line and 3D scanners. The use of line scanners allows detection and tracking at rates up to 75 Hz. However, this type of sensor may not always perform satisfactorily in uneven terrains. A 3D LADAR is used to improve operation in uneven terrains, by first estimating the local ground elevation, and then performing the detection using the measurements corresponding to a certain height above the ground. The information pipeline used to feed sensor data into the algorithm is the same for both types of sensors. The perceptual capabilities described aim to form the basis for safe and robust navigation in robotic vehicles, necessary to safeguard pedestrians operating in the vicinity of a moving robotic vehicle. T I.

Abstract — Situational awareness is crucial for autonomous driving in urban environments. This paper describes moving vehicle tracking module that we developed for our autonomous driving robot Junior. The robot won second place in the Urban Grand Challenge, an autonomous driving race organized by the U.S. Government in 2007. The tracking module provides reliable tracking of moving vehicles from a high-speed moving platform using laser range finders. Our approach models both dynamic and geometric properties of the tracked vehicles and estimates them using a single Bayes filter per vehicle. We also show how to build efficient 2D representations out of 3D range data and how to detect poorly visible black vehicles. Experimental validation includes the most challenging conditions presented at the UGC as well as other urban settings. I.

Abstract — Tracking in crowded urban areas is a daunting task. High crowdedness causes challenging data association problems. Different motion patterns from a wide variety of moving objects make motion modeling difficult. Accompanying with traditional motion modeling techniques, this paper introduces a scene interaction model and a neighboring object interaction model to respectively take long-term and short-term interactions between the tracked objects and its surroundings into account. With the use of the interaction models, anomalous activity recognition is accomplished easily. In addition, movestop hypothesis tracking is applied to deal with move-stopmove maneuvers. All these approaches are seamlessly intergraded under the variable-structure multiple-model estimation framework. The proposed approaches have been demonstrated using data from a laser scanner mounted on the PAL1 robot at a crowded intersection. Interacting pedestrians, bicycles, motorcycles, cars and trucks are successfully tracked in difficult situations with occlusion. I.

Abstract — This paper introduces a Bayesian filter that is specifically designed for counting targets that move outside of the field of view while performing a sensor sweep. Information space concepts are used to dramatically reduce the filter complexity so that information is processed only when the shadow region (all points invisible to the sensors) changes combinatorially or targets pass in and out of view. Previous work assumed perfect observations; however, this paper extends the approach to enable probabilistic disturbances. Practical algorithms are introduced, implemented, and demonstrated for computing the filter outputs based on realistic data. (a) (b)

Autonomous service robots that assist in housekeeping, serve as butlers, guide visitors through exhibitions in museums and trade fairs, or provide care to elderly and disabled people could substantially ease everyday life for many people and present an enormous economic

Abstract. The neural representation of space in rats has inspired many navigation systems for robots. In particular, Self-Organizing (Feature) Maps (SOM) are often used to give a sense of location to robots by mapping sensor information to a low-dimensional grid. For example, a robot equipped with a panoramic camera can build a 2D SOM from vectors of landmark bearings. If there are four landmarks in the robot’s environment, then the 2D SOM is embedded in a 2D manifold lying in a 4D space. In general, the set of observable sensor vectors form a low-dimensional Riemannian manifold in a high-dimensional space. In a landmark bearing sensor space, the manifold can have a large curvature in some regions (when the robot is near a landmark for example), making the Eulidian distance a very poor approximation of the Riemannian metric. In this paper, we present and compare three methods for measuring the similarity between vectors of landmark bearings. We also discuss a method to equip SOM with a good approximation of the Riemannian metric. Although we illustrate the techniques with a landmark bearing problem, our approach is applicable to other types of data sets. 1