Search

This paper proposes a distributed estimation and control algorithm that enables a team of mobile robots to search for and track an unknown number of targets. These targets may be stationary or moving, and the number of targets may vary over time as targets enter and leave the area of interest. The robots are equipped with sensors that have a finite field of view and may experience false negative and false positive detections. The robots use a novel, distributed formulation of the Probability Hypothesis Density (PHD) filter, which accounts for the limitations of the sensors, to estimate the number of targets and the positions of the targets. The robots then use Lloyd's algorithm, a distributed control algorithm that has been shown to be effective for coverage and search tasks, to drive their motion within the environment. We utilize the output of the PHD filter as the importance weighting function within Lloyd's algorithm. This causes the robots to be drawn towards areas that are likely to contain targets. We demonstrate the efficacy of our proposed algorithm, including comparisons to a coverage-based controller with a uniform importance weighting function, through an extensive series of simulated experiments. These experiments show teams of 10–100 robots successfully tracking 10–50 targets in both 2D and 3D environments. [ABSTRACT FROM AUTHOR]

This paper presents an automated robotic system for generating semantic maps of inventory in retail environments. In retail settings, semantic maps are labeled maps of stores where each discrete section of shelving is assigned a department label describing the types of products on that shelf. Starting from a metric map of the store, the robot autonomously extracts the shelf boundaries, generates a distance-optimal tour of the store to view every shelf, and follows the tour while avoiding unmapped clutter and moving people. The robot creates a point cloud of the store using the data collected from this tour. We introduce a novel soft-object assignment algorithm to create a virtual map and a dynamic programming algorithm to segment this map. These algorithms use a priori information about the products to boost data from laser and camera sensors in order to recognize and semantically label objects. The primary contribution of this paper is the integration of multiple systems for automated path planning, navigation, object recognition, and semantic mapping. This paper represents an important contribution toward deploying mobile robots in dynamic human environments. [ABSTRACT FROM AUTHOR]

This paper considers situations in which a team of mobile sensor platforms autonomously explores an environment to detect and localize an unknown number of targets. Individual sensors may be unreliable, failing to detect objects within the field-of-view, returning false positive measurements to clutter objects, and being unable to disambiguate true targets. In this setting, data association is difficult. We utilize the PHD filter for multitarget localization, simultaneously estimating the number of objects and their locations within the environment without the need to explicitly consider data association. Using sets of potential actions generated at multiple length scales for each robot, the team selects the joint action that maximizes the expected information gain over a finite time horizon. This is computed as the mutual information between the set of targets and the binary events of receiving no detections, effectively hedging against uninformative actions in a computationally tractable manner. We frame the controller as a receding-horizon problem. We demonstrate the real-world applicability of the proposed autonomous exploration strategy through hardware experiments, exploring an office environment with a team of ground robots. We also conduct a series of simulated experiments, varying the planning method, target cardinality, environment, and sensor modality. [ABSTRACT FROM PUBLISHER]

The publication offers a note of thanks and lists its reviewers. [ABSTRACT FROM PUBLISHER]