Kristopher R. Beevers

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When multiple robots cooperatively explore an environment, maps from individual robots must be merged to produce a single globally consistent map. This is a difficult problem when the robots do not have a common reference frame or global positioning. In this paper, we describe an algorithm for merging embedded topological maps. Topological maps provide a(More)
Most work on the simultaneous localization and mapping (SLAM) problem assumes the frequent availability of dense information about the environment such as that provided by a laser rangefinder. However, for implementing SLAM in consumer-oriented products such as toys or cleaning robots, it is infeasible to use expensive sensing. In this work we examine the(More)
We describe two new sampling strategies for Rao-Blackwellized particle filtering SLAM. The strategies, called fixed-lag roughening and the block proposal distribution, both exploit "future" information, when it becomes available, to improve the filter's estimation for previous time steps. Fixed-lag roughening perturbs trajectory samples over a fixed lag(More)
In order to create consistent maps of unknown environments, a robot must be able to recognize when it has returned to a previously visited place. In this paper, we introduce an evidential approach to the loop-closing problem for topological maps, based on the Dempster-Shafer theory of evidence. In our approach, the robot makes a hypothesis whenever it may(More)
We describe several new sampling strategies for Rao-Blackwellized particle filtering SLAM. Two of the strategies, called fixed-lag roughening and the block proposal distribution, attempt to exploit “future” information, when it becomes available, to improve the filter’s estimation for previous time steps. Fixed-lag roughening perturbs trajectory samples(More)
Definition 1.1. A stochastic process is a collection of random variables X1,X2, . . . ,Xt parameterized by time. There are a number of aspects of a stochastic process that we can examine. Among them: • dependencies between variables in the sequence • various kinds of long-term averages • the frequency at which “boundary events” occur Some examples of(More)