861 research outputs found
Simple yet stable bearing-only navigation
This article describes a simple monocular navigation system for a mobile robot based on the map-and-replay technique. The presented method is robust and easy to implement and does not require sensor calibration or structured environment, and its computational complexity is independent of the environment size. The method can navigate a robot while sensing only one landmark at a time, making it more robust than other monocular approaches. The aforementioned properties of the method allow even low-cost robots to effectively act in large outdoor and indoor environments with natural landmarks only. The basic idea is to utilize a monocular vision to correct only the robot's heading, leaving distance measurements to the odometry. The heading correction itself can suppress the odometric error and prevent the overall position error from diverging. The influence of a map-based heading estimation and odometric errors on the overall position uncertainty is examined. A claim is stated that for closed polygonal trajectories, the position error of this type of navigation does not diverge. The claim is defended mathematically and experimentally. The method has been experimentally tested in a set of indoor and outdoor experiments, during which the average position errors have been lower than 0.3 m for paths more than 1 km long
A review on humanoid robotics in healthcare
Humanoid robots have evolved over the years and today it is in many different areas of applications, from homecare to social care and healthcare robotics. This paper deals with a brief overview of the current and potential applications of humanoid robotics in healthcare settings. We present a comprehensive contextualization of humanoid robots in healthcare by identifying and characterizing active research activities on humanoid robot that can work interactively and effectively with humans so as to fill some identified gaps in current healthcare deficiency
Design, Field Evaluation, and Traffic Analysis of a Competitive Autonomous Driving Model in a Congested Environment
Recently, numerous studies have investigated cooperative traffic systems
using the communication among vehicle-to-everything (V2X). Unfortunately, when
multiple autonomous vehicles are deployed while exposed to communication
failure, there might be a conflict of ideal conditions between various
autonomous vehicles leading to adversarial situation on the roads. In South
Korea, virtual and real-world urban autonomous multi-vehicle races were held in
March and November of 2021, respectively. During the competition, multiple
vehicles were involved simultaneously, which required maneuvers such as
overtaking low-speed vehicles, negotiating intersections, and obeying traffic
laws. In this study, we introduce a fully autonomous driving software stack to
deploy a competitive driving model, which enabled us to win the urban
autonomous multi-vehicle races. We evaluate module-based systems such as
navigation, perception, and planning in real and virtual environments.
Additionally, an analysis of traffic is performed after collecting multiple
vehicle position data over communication to gain additional insight into a
multi-agent autonomous driving scenario. Finally, we propose a method for
analyzing traffic in order to compare the spatial distribution of multiple
autonomous vehicles. We study the similarity distribution between each team's
driving log data to determine the impact of competitive autonomous driving on
the traffic environment
System of Terrain Analysis, Energy Estimation and Path Planning for Planetary Exploration by Robot Teams
NASA’s long term plans involve a return to manned moon missions, and eventually sending humans to mars. The focus of this project is the use of autonomous mobile robotics to enhance these endeavors. This research details the creation of a system of terrain classification, energy of traversal estimation and low cost path planning for teams of inexpensive and potentially expendable robots.
The first stage of this project was the creation of a model which estimates the energy requirements of the traversal of varying terrain types for a six wheel rocker-bogie rover. The wheel/soil interaction model uses Shibly’s modified Bekker equations and incorporates a new simplified rocker-bogie model for estimating wheel loads. In all but a single trial the relative energy requirements for each soil type were correctly predicted by the model.
A path planner for complete coverage intended to minimize energy consumption was designed and tested. It accepts as input terrain maps detailing the energy consumption required to move to each adjacent location. Exploration is performed via a cost function which determines the robot’s next move. This system was successfully tested for multiple robots by means of a shared exploration map. At peak efficiency, the energy consumed by our path planner was only 56% that used by the best case back and forth coverage pattern.
After performing a sensitivity analysis of Shibly’s equations to determine which soil parameters most affected energy consumption, a neural network terrain classifier was designed and tested. The terrain classifier defines all traversable terrain as one of three soil types and then assigns an assumed set of soil parameters. The classifier performed well over all, but had some difficulty distinguishing large rocks from sand.
This work presents a system which successfully classifies terrain imagery into one of three soil types, assesses the energy requirements of terrain traversal for these soil types and plans efficient paths of complete coverage for the imaged area. While there are further efforts that can be made in all areas, the work achieves its stated goals
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