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Open AccessArticle

Autonomous Navigation System of Indoor Mobile Robots Using 2D Lidar

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Mathematics 2023, 11(6), 1455; https://doi.org/10.3390/math11061455 - 17 Mar 2023

Viewed by 275

Abstract

Significant developments have been made in the navigation of autonomous mobile robots within indoor environments; however, there still remain challenges in the face of poor map construction accuracy and suboptimal path planning, which limit the practical applications of such robots. To solve these [...] Read more.

Significant developments have been made in the navigation of autonomous mobile robots within indoor environments; however, there still remain challenges in the face of poor map construction accuracy and suboptimal path planning, which limit the practical applications of such robots. To solve these challenges, an enhanced Rao Blackwell Particle Filter (RBPF-SLAM) algorithm, called Lidar-based RBPF-SLAM (LRBPF-SLAM), is proposed. In LRBPF, the adjacent bit poses difference data from the 2D Lidar sensor which is used to replace the odometer data in the proposed distribution function, overcoming the vulnerability of the proposed distribution function to environmental disturbances, and thus enabling more accurate pose estimation of the robot. Additionally, a probabilistic guided search-based path planning algorithm, gravitation bidirectional rapidly exploring random tree (GBI-RRT), is also proposed, which incorporates a target bias sampling to efficiently guide nodes toward the goal and reduce ineffective searches. Finally, to further improve the efficiency of navigation, a path reorganization strategy aiming at eliminating low-quality nodes and improving the path curvature of the path is proposed. To validate the effectiveness of the proposed method, the improved algorithm is integrated into a mobile robot based on a ROS system and evaluated in simulations and field experiments. The results show that LRBPF-SLAM and GBI-RRT perform superior to the existing algorithms in various indoor environments. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Open AccessArticle

Explicit Identification of Pointwise Terrain Gradients for Speed Compensation of Four Driving Tracks in Passively Articulated Tracked Mobile Robot

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Haneul Jeon

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Donghun Lee

Mathematics 2023, 11(4), 905; https://doi.org/10.3390/math11040905 - 10 Feb 2023

Viewed by 364

Abstract

Tracked mobile robots can overcome the limitations of wheeled and legged robots in environments, such as construction and mining, but there are still significant challenges to be addressed in terms of trajectory tracking. This study proposes a kinematic strategy to improve the trajectory-tracking [...] Read more.

Tracked mobile robots can overcome the limitations of wheeled and legged robots in environments, such as construction and mining, but there are still significant challenges to be addressed in terms of trajectory tracking. This study proposes a kinematic strategy to improve the trajectory-tracking performance of a PASTRo (Passively Articulated Suspension based Track-typed mobile robot), which comprises four tracks, two rockers, a differential gear, and a main body. Due to the difficulties in explicitly identifying track-terrain contact angles, suspension kinematics is used to identify track-terrain contact angles (TTCA) in arbitrarily rough terrains. Thus, the TTCA-based driving velocity projection method is proposed in this study to improve the maneuverability of PASTRo in arbitrarily rough terrains. The RecurDyn-Simulink co-simulator is used to examine the improvement of PASTRo compared to a tracked mobile robot non-suspension version. The results indicate that PASTRo has a 33.3% lower RMS(Root Mean Square) distance error, 56.3% lower RMS directional error, and 43.2% lower RMS offset error than the four-track skid-steer mobile robot (SSMR), even with planar SSMR kinematics. To improve the maneuverability of PASTRo without any information on the rough terrain, the TTCA is calculated from the suspension kinematics, and the TTCA obtained is used for both TTCA-based driving velocity projection methods. The results show that PASTRo, with the TTCA-based driving velocity projection method, has a 39.2% lower RMS distance error, 57.9% lower RMS directional error, and 51.9% lower RMS offset error than the four-track SSMR. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Open AccessArticle

A Cooperative Control Algorithm for Line and Predecessor Following Platoons Subject to Unreliable Distance Measurements

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Mathematics 2023, 11(4), 801; https://doi.org/10.3390/math11040801 - 04 Feb 2023

Viewed by 368

Abstract

This paper uses a line-following approach to study the longitudinal and lateral problems in vehicle platooning. Under this setup, we assume that inter-vehicle distance sensing is unreliable and propose a cooperative control strategy to render the platoon less vulnerable to these sensing difficulties. [...] Read more.

This paper uses a line-following approach to study the longitudinal and lateral problems in vehicle platooning. Under this setup, we assume that inter-vehicle distance sensing is unreliable and propose a cooperative control strategy to render the platoon less vulnerable to these sensing difficulties. The proposed control scheme uses the velocity of the predecessor vehicle, communicated through a Vehicle-to-Vehicle technology, to avoid significant oscillations in the local speed provoked by tracking using unreliable local distance measurements. We implement the proposed control algorithm in the RUPU platform, a low-cost experimental platform with wireless communication interfaces that enable the implementation of cooperative control schemes for mobile agent platooning. The experiments show the effectiveness of the proposed cooperative control scheme in maintaining a suitable performance even when subject to temporal distortions in local measurements, which, in the considered experimental setup, arise from losing the line-of-sight of the local sensors in paths with closed curves. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Open AccessArticle

Active Disturbance Rejection Strategy for Distance and Formation Angle Decentralized Control in Differential-Drive Mobile Robots

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Mario Ramírez-Neria

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Jaime González-Sierra

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Alberto Luviano-Juárez

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Norma Lozada-Castillo

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Rafal Madonski

Mathematics 2022, 10(20), 3865; https://doi.org/10.3390/math10203865 - 18 Oct 2022

Viewed by 743

Abstract

The important practical problem of robust synchronization in distance and orientation for a class of differential-drive mobile robots is tackled in this work as an active disturbance rejection control (ADRC) problem. To solve it, a kinematic model of the governed system is first [...] Read more.

The important practical problem of robust synchronization in distance and orientation for a class of differential-drive mobile robots is tackled in this work as an active disturbance rejection control (ADRC) problem. To solve it, a kinematic model of the governed system is first developed based on the distance and formation angle between the agents. Then, a special high-order extended state observer is designed to collectively estimate the perturbations (formed by longitudinal and lateral slipping parameters) that affect the kinematic model. Finally, a custom error-based ADRC approach is designed and applied assuming that the distance and orientation between the agents are the only available measurements. The proposed control strategy does not need time-derivatives of the reference trajectory, which increases the practical appeal of the proposed solution. The experimental results, obtained in laboratory conditions with a set of differential-drive mobile robots operating in a leader–follower configuration, show the effectiveness of the proposed governing scheme in terms of trajectory tracking and disturbance rejection. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Open AccessArticle

Kinematic Modelling for Hyper-Redundant Robots—A Structured Guide

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Diego Cerrillo

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Antonio Barrientos

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Jaime Del Cerro

Mathematics 2022, 10(16), 2891; https://doi.org/10.3390/math10162891 - 12 Aug 2022

Cited by 1 | Viewed by 755

Abstract

Obtaining mathematical equations to model the kinematics of a hyper-redundant robot is not intuitive and of greater difficulty than for traditional robots. Depending on the characteristics of the robot, the most appropriate methodology to approach the modelling may be one or another. This [...] Read more.

Obtaining mathematical equations to model the kinematics of a hyper-redundant robot is not intuitive and of greater difficulty than for traditional robots. Depending on the characteristics of the robot, the most appropriate methodology to approach the modelling may be one or another. This article provides a general overview of the different approaches there are when modelling a hyper-redundant cable-driven robot, while proposing a guide to help the novel researcher that approaches this field decide which methodology to apply when modelling a robot. After providing some definitions, a simple framework to understand all the underlying models is presented. Afterwards, the mathematical equations for the most important methods of modelling are developed. Finally, the proposal for a step-by-step tutorial is included, and it is exemplified by applying it to three real robots. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Open AccessArticle

Towards the Sign Function Best Approximation for Secure Outsourced Computations and Control

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Mikhail Babenko

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Andrei Tchernykh

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Bernardo Pulido-Gaytan

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Mathematics 2022, 10(12), 2006; https://doi.org/10.3390/math10122006 - 10 Jun 2022

Viewed by 728

Abstract

Homomorphic encryption with the ability to compute over encrypted data without access to the secret key provides benefits for the secure and powerful computation, storage, and communication of resources in the cloud. One of its important applications is fast-growing robot control systems for [...] Read more.

Homomorphic encryption with the ability to compute over encrypted data without access to the secret key provides benefits for the secure and powerful computation, storage, and communication of resources in the cloud. One of its important applications is fast-growing robot control systems for building lightweight, low-cost, smarter robots with intelligent brains consisting of data centers, knowledge bases, task planners, deep learning, information processing, environment models, communication support, synchronous map construction and positioning, etc. It enables robots to be endowed with secure, powerful capabilities while reducing sizes and costs. Processing encrypted information using homomorphic ciphers uses the sign function polynomial approximation, which is a widely studied research field with many practical results. State-of-the-art works are mainly focused on finding the polynomial of best approximation of the sign function (PBAS) with the improved errors on the union of the intervals

[- 1, - ϵ] \cup^{} [ϵ, 1]

. However, even though the existence of the single PBAS with the minimum deviation is well known, its construction method on the complete interval

[- 1, 1]

is still an open problem. In this paper, we provide the PBAS construction method on the interval

[- 1, 1]

, using as a norm the area between the sign function and the polynomial and showing that for a polynomial degree

n \geq 1

, there is (1) unique PBAS of the odd sign function, (2) no PBAS of the general form sign function if

n

is odd, and (3) an uncountable set of PBAS, if

n

is even. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Open AccessArticle

Predicate-Based Model of Problem-Solving for Robotic Actions Planning

by

Oleksandr Tsymbal

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Paolo Mercorelli

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Oleg Sergiyenko

Mathematics 2021, 9(23), 3044; https://doi.org/10.3390/math9233044 - 26 Nov 2021

Cited by 5 | Viewed by 939

Abstract

The aim of the article is to describe a predicate-based logical model for the problem-solving of robots. The proposed article deals with analyses of trends of problem-solving robotic applications for manufacturing, especially for transportations and manipulations. Intelligent agent-based manufacturing systems with robotic agents [...] Read more.

The aim of the article is to describe a predicate-based logical model for the problem-solving of robots. The proposed article deals with analyses of trends of problem-solving robotic applications for manufacturing, especially for transportations and manipulations. Intelligent agent-based manufacturing systems with robotic agents are observed. The intelligent cores of them are considered from point of view of ability to propose the plans of problem-solving in the form of strategies. The logical model of adaptive strategies planning for the intelligent robotic system is composed in the form of predicates with a presentation of data processing on a base of set theory. The dynamic structures of workspaces, and a possible change of goals are considered as reasons for functional strategies adaptation. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Open AccessArticle

Adaptive Active Disturbance Rejection Control of Solar Tracking Systems with Partially Known Model

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Sergio Isai Palomino-Resendiz

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Norma Beatriz Lozada-Castillo

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Diego Alonso Flores-Hernández

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Oscar Octavio Gutiérrez-Frías

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Alberto Luviano-Juárez

Mathematics 2021, 9(22), 2871; https://doi.org/10.3390/math9222871 - 11 Nov 2021

Cited by 1 | Viewed by 1126

Abstract

In this article, the trajectory tracking control of a solar tracking system is tackled by means of an adaptive active disturbance rejection control scheme. The state and disturbance estimation system is based on the combination of a time varying identification system and an [...] Read more.

In this article, the trajectory tracking control of a solar tracking system is tackled by means of an adaptive active disturbance rejection control scheme. The state and disturbance estimation system is based on the combination of a time varying identification system and an adaptive observer. The stability and robustness of the controller is mathematically tested by means of the second method of Lyapunov, and its effectiveness is experimentally tested in a robotic test bed, achieving both lower energy consumption and better tracking results with respect to a PID-based controller. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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Review

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Open AccessReview

Concrete 3D Printing: Process Parameters for Process Control, Monitoring and Diagnosis in Automation and Construction

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Mathematics 2023, 11(6), 1499; https://doi.org/10.3390/math11061499 - 19 Mar 2023

Viewed by 275

Abstract

In Singapore, there is an increasing need for independence from manpower within the Building and Construction (B&C) Industry. Prefabricated Prefinished Volumetric Construction (PPVC) production is mainly driven by benefits in environmental pollution reduction, improved productivity, quality control, and customizability. However, overall cost savings [...] Read more.

In Singapore, there is an increasing need for independence from manpower within the Building and Construction (B&C) Industry. Prefabricated Prefinished Volumetric Construction (PPVC) production is mainly driven by benefits in environmental pollution reduction, improved productivity, quality control, and customizability. However, overall cost savings have been counterbalanced by new cost drivers like modular precast moulds, transportation, hoisting, manufacturing & holding yards, and supervision costs. The highly modular requirements for PPVC places additive manufacturing in an advantageous position, due to its high customizability, low volume manufacturing capabilities for a faster manufacturing response time, faster production changeovers, and lower inventory requirements. However, C3DP has only just begun to move away from its early-stage development, where there is a need to closely evaluate the process parameters across buildability, extrudability, and pumpability aspects. As many parameters have been identified as having considerable influence on C3DP processes, monitoring systems for feedback applications seem to be an inevitable step forward to automation in construction. This paper has presented a broad analysis of the challenges posed to C3DP and feedback systems, stressing the admission of process parameters to correct multiple modes of failure. Full article

(This article belongs to the Special Issue Mathematics in Robot Control for Theoretical and Applied Problems)

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