447 research outputs found
Wheeled Mobile Robots: State of the Art Overview and Kinematic Comparison Among Three Omnidirectional Locomotion Strategies
In the last decades, mobile robotics has become a very interesting research topic in the feld of robotics, mainly because of population ageing and the recent pandemic emergency caused by Covid-19. Against this context, the paper presents an overview on wheeled mobile robot (WMR), which have a central role in nowadays scenario. In particular, the paper describes the most commonly adopted locomotion strategies, perception systems, control architectures and navigation approaches. After having analyzed the state of the art, this paper focuses on the kinematics of three omnidirectional platforms: a four mecanum wheels robot (4WD), a three omni wheel platform (3WD) and a two swerve-drive system (2SWD). Through a dimensionless approach, these three platforms are compared to understand how their mobility is afected by the wheel speed limitations that are present in every practical application. This original comparison has not been already presented by the literature and it can be used to improve our understanding of the kinematics of these mobile robots and to guide the selection of the most appropriate locomotion system according to the specifc application
Kinematic Analysis of Omnidirectional Mecanum wheeled Robot
This study used the V-rep simulation environment to develop an omnidirectional, four-wheeled Robot model and perform kinematic analysis using youBot. Given their extensive use, it is essential to understand how Mecanum wheels' speeds convert into robot velocities before moving on to a dynamic model that governs how wheel torques translate into robot accelerations. This paper investigates the rate at which the wheels must be driven given the desired chassis velocity, also limit on the chassis velocity, given a limit on the individual wheel operating speed
Kinematic Analysis of Omnidirectional Mecanum wheeled Robot
This study used the V-rep simulation environment to develop an omnidirectional, four-wheeled Robot model and perform kinematic analysis using youBot. Given their extensive use, it is essential to understand how Mecanum wheels' speeds convert into robot velocities before moving on to a dynamic model that governs how wheel torques translate into robot accelerations. This paper investigates the rate at which the wheels must be driven given the desired chassis velocity, also limit on the chassis velocity, given a limit on the individual wheel operating speed
Localization, Navigation and Activity Planning for Wheeled Agricultural Robots – A Survey
Source at:https://fruct.org/publications/volume-32/fruct32/High cost, time intensive work, labor shortages
and inefficient strategies have raised the need of employing
mobile robotics to fully automate agricultural tasks and fulfil
the requirements of precision agriculture. In order to perform
an agricultural task, the mobile robot goes through a sequence
of sub operations and integration of hardware and software
systems. Starting with localization, an agricultural robot uses
sensor systems to estimate its current position and orientation in
field, employs algorithms to find optimal paths and reach target
positions. It then uses techniques and models to perform feature
recognition and finally executes the agricultural task through
an end effector. This article, compiled through scrutinizing the
current literature, is a step-by-step approach of the strategies and
ways these sub-operations are performed and integrated together.
An analysis has also been done on the limitations in each sub
operation, available solutions, and the ongoing research focus
Preliminary laboratory test on navigation accuracy of an autonomous robot for measuring air quality in livestock buildings
Air quality in many poultry buildings is less than desirable. However, the measurement of concentrations of airborne pollutants in livestock buildings is generally quite difficult. To counter this, the development of an autonomous robot that could collect key environmental data continuously in livestock buildings was initiated. This research presents a specific part of the larger study that focused on the preliminary laboratory test for evaluating the navigation precision of the robot being developed under the different ground surface conditions and different localization algorithm according internal sensors. The construction of the robot was such that each wheel of the robot was driven by an independent DC motor with four odometers fixed on each motor. The inertial measurement unit (IMU) was rigidly fixed on the robot vehicle platform. The research focused on using the internal sensors to calculate the robot position (x, y, θ) through three different methods. The first method relied only on odometer dead reckoning (ODR), the second method was the combination of odometer and gyroscope data dead reckoning (OGDR) and the last method was based on Kalman filter data fusion algorithm (KFDF). A series of tests were completed to generate the robot’s trajectory and analyse the localisation accuracy. These tests were conducted on different types of surfaces and path profiles. The results proved that the ODR calculation of the position of the robot is inaccurate due to the cumulative errors and the large deviation of the heading angle estimate. However, improved use of the gyroscope data of the IMU sensor improved the accuracy of the robot heading angle estimate. The KFDF calculation resulted in a better heading angle estimate than the ODR or OGDR calculations. The ground type was also found to be an influencing factor of localisation errors
Modified Q-Learning Algorithm for Mobile Robot Path Planning Variation using Motivation Model
Path planning is an essential algorithm in autonomous mobile robots, including agricultural robots, to find the shortest path and to avoid collisions with obstacles. Q-Learning algorithm is one of the reinforcement learning methods used for path planning. However, for multi-robot system, this algorithm tends to produce the same path for each robot. This research modifies the Q-Learning algorithm in order to produce path variations by utilizing the motivation model, i.e. achievement motivation, in which different motivation parameters will result in different optimum paths. The Motivated Q-Learning (MQL) algorithm proposed in this study was simulated in an area with three scenarios, i.e. without obstacles, uniform obstacles, and random obstacles. The results showed that, in the determined scenario, the MQL can produce 2 to 4 variations of optimum path without any potential of collisions (Jaccard similarity = 0%), in contrast to the Q-Learning algorithm that can only produce one optimum path variation. This result indicates that MQL can solve multi-robots path planning problems, especially when the number of robots is large, by reducing the possibility of collisions as well as decreasing the problem of queues. However, the average computational time of the MQL is slightly longer than that of the Q-Learning
Motion Planning
Motion planning is a fundamental function in robotics and numerous intelligent machines. The global concept of planning involves multiple capabilities, such as path generation, dynamic planning, optimization, tracking, and control. This book has organized different planning topics into three general perspectives that are classified by the type of robotic applications. The chapters are a selection of recent developments in a) planning and tracking methods for unmanned aerial vehicles, b) heuristically based methods for navigation planning and routes optimization, and c) control techniques developed for path planning of autonomous wheeled platforms
Industrial, Collaborative and Mobile Robotics in Latin America: Review of Mechatronic Technologies for Advanced Automation
Mechatronics and Robotics (MaR) have recently gained importance in product development and manufacturing settings and applications. Therefore, the Center for Space Emerging Technologies (C-SET) has managed an international multi-disciplinary study to present, historically, the first Latin American general review of industrial, collaborative, and mobile robotics, with the support of North American and European researchers and institutions. The methodology is developed by considering literature extracted from Scopus, Web of Science, and Aerospace Research Central and adding reports written by companies and government organizations. This describes the state-of-the-art of MaR until the year 2023 in the 3 Sub-Regions: North America, Central America, and South America, having achieved important results related to the academy, industry, government, and entrepreneurship; thus, the statistics shown in this manuscript are unique. Also, this article explores the potential for further work and advantages described by robotic companies such as ABB, KUKA, and Mecademic and the use of the Robot Operating System (ROS) in order to promote research, development, and innovation. In addition, the integration with industry 4.0 and digital manufacturing, architecture and construction, aerospace, smart agriculture, artificial intelligence, and computational social science (human-robot interaction) is analyzed to show the promising features of these growing tech areas, considering the improvements to increase production, manufacturing, and education in the Region. Finally, regarding the information presented, Latin America is considered an important location for investments to increase production and product development, taking into account the further proposal for the creation of the LATAM Consortium for Advanced Robotics and Mechatronics, which could support and work on roboethics and education/R+D+I law and regulations in the Region. Doi: 10.28991/ESJ-2023-07-04-025 Full Text: PD
An Approach for Multi-Robot Opportunistic Coexistence in Shared Space
This thesis considers a situation in which multiple robots operate in the
same environment towards the achievement of different tasks. In this situation,
please consider that not only the tasks, but also the robots themselves
are likely be heterogeneous, i.e., different from each other in their
morphology, dynamics, sensors, capabilities, etc. As an example, think
about a "smart hotel": small wheeled robots are likely to be devoted to
cleaning floors, whereas a humanoid robot may be devoted to social interaction,
e.g., welcoming guests and providing relevant information to
them upon request.
Under these conditions, robots are required not only to co-exist, but also
to coordinate their activity if we want them to exhibit a coherent and
effective behavior: this may range from mutual avoidance to avoid collisions,
to a more explicit coordinated behavior, e.g., task assignment or
cooperative localization.
The issues above have been deeply investigated in the Literature. Among
the topics that may play a crucial role to design a successful system, this
thesis focuses on the following ones:
(i) An integrated approach for path following and obstacle avoidance is
applied to unicycle type robots, by extending an existing algorithm [1]
initially developed for the single robot case to the multi-robot domain.
The approach is based on the definition of the path to be followed as a
curve f (x;y) in space, while obstacles are modeled as Gaussian functions
that modify the original function, generating a resulting safe path. The
attractiveness of this methodology which makes it look very simple, is
that it neither requires the computation of a projection of the robot position
on the path, nor does it need to consider a moving virtual target
to be tracked. The performance of the proposed approach is analyzed
by means of a series of experiments performed in dynamic environments
with unicycle-type robots by integrating and determining the position of
robot using odometry and in Motion capturing environment.
(ii) We investigate the problem of multi-robot cooperative localization
in dynamic environments. Specifically, we propose an approach where
wheeled robots are localized using the monocular camera embedded in
the head of a Pepper humanoid robot, to the end of minimizing deviations
from their paths and avoiding each other during navigation tasks.
Indeed, position estimation requires obtaining a linear relationship between
points in the image and points in the world frame: to this end, an
Inverse Perspective mapping (IPM) approach has been adopted to transform
the acquired image into a bird eye view of the environment. The
scenario is made more complex by the fact that Pepper\u2019s head is moving
dynamically while tracking the wheeled robots, which requires to consider
a different IPM transformation matrix whenever the attitude (Pitch
and Yaw) of the camera changes. Finally, the IPM position estimate returned
by Pepper is merged with the estimate returned by the odometry
of the wheeled robots through an Extened Kalman Filter. Experiments
are shown with multiple robots moving along different paths in a shared
space, by avoiding each other without onboard sensors, i.e., by relying
only on mutual positioning information.
Software for implementing the theoretical models described above have
been developed in ROS, and validated by performing real experiments
with two types of robots, namely: (i) a unicycle wheeled Roomba robot(commercially available all over the world), (ii) Pepper Humanoid robot
(commercially available in Japan and B2B model in Europe)
Autonomous surveillance for biosecurity
The global movement of people and goods has increased the risk of biosecurity
threats and their potential to incur large economic, social, and environmental
costs. Conventional manual biosecurity surveillance methods are limited by
their scalability in space and time. This article focuses on autonomous
surveillance systems, comprising sensor networks, robots, and intelligent
algorithms, and their applicability to biosecurity threats. We discuss the
spatial and temporal attributes of autonomous surveillance technologies and map
them to three broad categories of biosecurity threat: (i) vector-borne
diseases; (ii) plant pests; and (iii) aquatic pests. Our discussion reveals a
broad range of opportunities to serve biosecurity needs through autonomous
surveillance.Comment: 26 pages, Trends in Biotechnology, 3 March 2015, ISSN 0167-7799,
http://dx.doi.org/10.1016/j.tibtech.2015.01.003.
(http://www.sciencedirect.com/science/article/pii/S0167779915000190
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