Vision-based formation control of mobile robots

1Introduction Formation control of multiple vehicles,such ascooperative control of a group of mobile robots[1~4]and multiple spacecraft[5,6],has beenrecognized as a keytechnologyfor the future and studied by many researchersin recent years.The various control approaches to multiplevehicle formation reported in the literature can becategorized into three groups:leader following schemes;behavior_based methods;and virtual structure techniques.In the leader following approach[1,2,7],one of thevehi…     

A robust anti-windup control design for electrically driven robots — Theory and experiment

A Robust Anti-Windup Control (RAWC) method is proposed for n-Degree-of-Freedom (DOF) electrically driven robots considering the actuator voltage saturation. The actuator’s saturation is fairly modeled by a smooth nonlinear function and the control design task is developed to avoid windup besides being robust against both model uncertainties and external disturbances. As a major point, the paper also takes into consideration the fact that windup phenomenon can be caused by some strong disturbances. As a result, being robust to external disturbances promises safer situation against windup. The proposed controller needs no saturation output feedback and torque’s measurement for control implementation. The analytical studies as well as the experimental results produced using MATLAB/SIMULINK External Mode Control on a 2-DOF robot manipulator driven by geared Permanent magnet DC motors prove the superiority of the proposed approach.     

Integrating planning and control for single-bodied wheeled mobile robots

This paper presents an approach to couple path planning and control for mobile robot navigation in a hybrid control framework. We build upon an existing hybrid control approach called sequential composition, in which a set of feedback control policies are prescribed on well-defined domains contained in the robot’s free space. Each control policy drives the robot to a goal set, which lies in the domain of a subsequent policy. Control policies are deployed into the free state space so that when composed among one another, the overall action of the set of control policies drives the robot to perform a task, such as moving from a start to a goal location or patrolling a perimeter. A planner determines the sequence of control policies to be invoked. When control policies defined in this framework respect the low-level dynamics and kinematics of the system, this formal approach guarantees that high-level tasks are either accomplished by a given set of policies, or verifies that the tasks are not achievable with the given policies.     

Self-assembly strategies in a group of autonomous mobile robots

Robots are said to be capable of self-assembly when they can autonomously form physical connections with each other. By examining different ways in which a system can use self-assembly (i.e., different strategies), we demonstrate and quantify the performance costs and benefits of (i) acting as a physically larger self-assembled entity, (ii) letting the system choose when and if to self-assemble, (iii) coordinating the sensing and actuation of the connected robots so that they respond to the environment as a single collective entity. Our analysis is primarily based on real world experiments in a hill crossing task. The configuration of the hill is not known by the robots in advance—the hill can be present or absent, and can vary in steepness and orientation. In some configurations, the robots can overcome the hill more quickly by navigating individually, while other configurations require the robots to self-assemble to overcome the hill. We demonstrate the applicability of our self-assembly strategies to two other tasks—hole crossing and robot rescue—for which we present further proof-of-concept experiments with real robots.     

Climbing robots for maintenance and inspections of vertical structures—A survey of design aspects and technologies

The maintenance and inspection of large vertical structures with autonomous systems is still an unsolved problem. A large number of different robots exist which are able to navigate on buildings, ship hulls or other human-made structures. But, most of these systems are limited to special situations or applications. This paper deals with different locomotion and adhesion methods for climbing robots and presents characteristics, challenges and applications for these systems. Based on a given set of requirements these principles are examined and in terms of a comprehensive state-of-the-art more than hundred climbing robots are presented. Finally, this schematics is applied to design aspects of a wall-climbing robot which should be able to inspect large concrete buildings.     

Situation awareness acquired from monitoring process plants – the Process Overview concept and measure

We introduce Process Overview, a situation awareness characterisation of the knowledge derived from monitoring process plants. Process Overview is based on observational studies of process control work in the literature. The characterisation is applied to develop a query-based measure called the Process Overview Measure. The goal of the measure is to improve coupling between situation and awareness according to process plant properties and operator cognitive work. A companion article presents the empirical evaluation of the Process Overview Measure in a realistic process control setting. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA based on data collected by process experts.

Practitioner Summary: The Process Overview Measure is a query-based measure for assessing operator situation awareness from monitoring process plants in representative settings.     

Relationship between familiarity and humanness of robots – quantification of psychological impressions toward humanoid robots

We investigate the relationships between familiarity and humanness of humanoids from psychological perspective of view. Two thousand six hundred and twenty-four people from their 10s to 70s in Japan evaluated familiarity and humanness of different 11 humanoids based on the psychological scales which are developed for evaluation of humanoids. Results showed that robot-like robots which have round shapes are evaluated higher in familiarity and lower in humanness than robot-like robots which have mechanic appearance. Androids which have totally human-like appearances are evaluated higher in humanness and familiarity than robots which are partly human-like, while one android was rated high in humanness but low in familiarity. Relatedly, repulsion which reflects a value toward the existence of humanoids bears a proportionate relationship to humanness. Higher humanness with humanoids related to higher repulsion. In sum, the relationship between familiarity and humanness is curvilinear, while repulsion and humanness shows a linear relationship. We discussed the importance of appearance of robots and interaction with robots to introduce robots toward ordinary people.     

Classification-based wheel slip detection and detector fusion for mobile robots on outdoor terrain

This paper introduces a signal-recognition based approach for detecting autonomous mobile robot immobilization on outdoor terrain. The technique utilizes a support vector machine classifier to form class boundaries in a feature space composed of statistics related to inertial and (optional) wheel speed measurements. The proposed algorithm is validated using experimental data collected with an autonomous robot operating in an outdoor environment. Additionally, two detector fusion techniques are proposed to combine the outputs of multiple immobilization detectors. One technique is proposed to minimize false immobilization detections. A second technique is proposed to increase overall detection accuracy while maintaining rapid detector response. The two fusion techniques are demonstrated experimentally using the detection algorithm proposed in this work and a dynamic model-based algorithm. It is shown that the proposed techniques can be used to rapidly and robustly detect mobile robot immobilization in outdoor environments, even in the absence of absolute position information.

Model referenced monitoring and diagnosis — application to the manufacturing system

This paper describes “model referenced monitoring and diagnosis” a systematic method of monitoring and diagnosis. In this method, a model is used either to generate standard values for the monitoring parameters, or to derive a systematic diagnostic algorithm. As examples of the model referenced monitoring in manufacturing systems, the cutting torque prediction system and tool breakage detection system are described. In the former example, the cutting torque values at each point in time, which can be used as reference values in monitoring the abnormal cutting condition, are evaluated based on a solid modelling system. In the latter, an autoregressive (AR) model is adaptively fitted to the cutting torque signal in order to detect any sudden change in the cutting state due to tool breakage. Two examples are also described for the case of model referenced diagnosis; the diagnosis of sequentially controlled machines using the state graph model, and diagnosis by means of a failure causality model. The former method is applicable to machines controlled by sequence control. Based on the state graph of the machine and the controller, the diagnostic programme can be generated in combination with the control programme. The failure causality model represents the propagation of the effects of failures in the machine. All possible combinations of failure causes are obtained by solving the simultaneous Boolean equations derived from the model.     

Latent heat storage — A new concept to control cooling water temperature

The applicability of a latent heat storage in order to control the outlet temperature of cooling water is analysed. The industrial application discussed here concerns the metal industry. The heat transfer at the storage is studied with different models. Details of the storage are analysed with the finite element method. A modified lumped heat capacity method is used in the simulation model. Water is used to charge and discharge the heat storage. The latent heat storage consists of encapsulated phase change material. The capsules are installed in a container. During production periods part of the surplus heat of the cooling water is stored and thus not emitted into the river. The stored heat is then discharged at nonproduction periods without exceeding the restriction of maximum water temperature. The paper presented here is a short version of a paper for Envirosoft 88 by Solmar and Loyd [1].     

Erratum to:Distributed active fault tolerant control design against actuator faults for multiple mobile robots

Erratum to:Control Theory and Technology,2019,17(4),367-381 DOI https://doi.Org/10.1007/s11768-019-9076-7 In the published article there are two typesetting errors:1)the paragraph below equation(27)at Page 375:"The differentiation of(26)is given by...."should be"The differentiation of(27)is given by....";and 2)the paragraph below equation(36)at Page 375:"Based on Gersgorin Circle Criterion[20],the eigenvalues of the Laplacian matrix in(38)are in the left-half plane.This implies that...the end of the proof".should be"Based on Gersgorin Circle Criterion[20],the eigenvalues of the Laplacian matrix in(36)are in the left-half plane.This implies that...the end of the proof."     

Sports analytics — Evaluation of basketball players and team performance

Given the recent trend in Data Science (DS) and Sports Analytics, an opportunity has arisen for utilizing Machine Learning (ML) and Data Mining (DM) techniques in sports. This paper reviews background and advanced basketball metrics used in National Basketball Association (NBA) and Euroleague games. The purpose of this paper is to benchmark existing performance analytics used in the literature for evaluating teams and players. Basketball is a sport that requires full set enumeration of parameters in order to understand the game in depth and analyze the strategy and decisions by minimizing unpredictability. This research provides valuable information for team and player performance basketball analytics to be used for better understanding of the game. Furthermore, these analytics can be used for team composition, athlete career improvement and assessing how this could be materialized for future predictions. Hence, critical analysis of these metrics are valuable tools for domain experts and decision makers to understand the strengths and weaknesses in the game, to better evaluate opponent teams, to see how to optimize performance indicators, to use them for team and player forecasting and finally to make better choices for team composition.     

A generic natural language interface for task planning — application to a mobile robot

This paper presents a generic natural language interface that can be applied to the teleoperation of different kinds of complex interactive systems. Through this interface the operators can ask for simple actions or more complex tasks to be executed by the system. Complex tasks will be decomposed into simpler actions generating a network of actions whose execution will result in the accomplishment of the required task. As a practical application, the system has been applied to the teleoperation of a real mobile robot, allowing the operator to move the robot in a partially structured environment through natural language sentences.     

Work capacity and anticipation in A.A. Ukhtomsky’s concept of dominance

This paper presents the results of theoretical and experimental investigations of human activity and anticipation based on A.A. Ukhtomsky’s concept of brain dominance – a non-equilibrium system-forming factor in living systems. Facts on the stages of dominance formation are presented in relation to the creative abilities of the human brain and the role of fatigue as a “lever” for increasing systems’ work capacity on the basis of “trace exaltation”. Individually, specific features of dominantogenesis are compared with variations in behavioural types. On the basis of chronotopic EEG analysis, we delineate cortical dominants that underlie individual specifics of cognitive processes. The relation is shown between anticipation and the “expansion of dominants” – the broadening of “distal perception” in time and space, as framed by A.A. Ukhtomsky.     

Leader–follower formation control of nonholonomic mobile robots based on a bioinspired neurodynamic based approach

This paper investigates the leader–follower formation control problem for nonholonomic mobile robots based on a bioinspired neurodynamics based approach. The trajectory tracking control for a single nonholonomic mobile robot is extended to the formation control for multiple nonholonomic mobile robots based on the backstepping technique, in which the follower can track its real-time leader by the proposed kinematic controller. An auxiliary angular velocity control law is proposed to guarantee the global asymptotic stability of the followers and to further guarantee the local asymptotic stability of the entire formation. Also a bioinspired neurodynamics based approach is further developed to solve the impractical velocity jumps problem. The rigorous proofs are given by using Lyapunov theory. Simulations are also given to verify the effectiveness of the theoretical results.     

Can mobile phone-based animated videos induce learning and technology adoption among low-literate farmers? A field experiment in Burkina Faso

ABSTRACT

This article explores an innovative approach to deliver information about new agricultural technology that combines a versatile and potentially lower cost method of developing animated videos with another low-cost method of sharing it on mobile devices (i.e. mobile phone). It describes a randomized controlled field experiment conducted in Burkina Faso to evaluate the effectiveness of animated videos shown on mobile phone compared with the traditional extension method (live demonstration) in inducing learning and adoption of two post-harvest technologies among low-literate farmers. Results suggest that video-based training was as effective as the traditional method in inducing learning and understanding. For technologies that farmers were already aware of animated video shown on the mobile phone was also as effective as live demonstration in inducing adoption. However, in transferring new technologies, the traditional method was more effective in inducing adoption at p?<?.10, but not at p?<?.05. Potential role of mobile phone-based videos as part of the agricultural extension system is discussed.     

A spatio-temporal constrained hierarchical scheduling strategy for multiple warehouse mobile robots under industrial cyber–physical system

The industrial cyber–physical system (ICPS) framework can reduce the computational load and improve task efficiency. This paper studies the ICPS-based scheduling strategy for multi-warehouse mobile robots (multi-WMRs). First of all, the possible congestion problem is considered in topological map modeling, which is transformed into a new path time cost index. Second, each robot independently executes the path planning algorithm, which realizes distributed path computation and takes time cost and destination distance into account. The improved task assignment strategy includes task evaluation and decision-making, which are considered part of the planning and help to improve task efficiency. Finally, the complete scheduling process is applied to the novel ICPS architecture, including cost evaluation, path planning, task assignment, and collision avoidance. In numerical experiments, the task efficiency has been increased by 24.8% to recent research and 14.59% to previous work. The average congestion time is reduced by 28.41%, and the planning time is reduced to 10.13% of the traditional method.     

Planetary rovers�� wheel�Csoil interaction mechanics: new challenges and applications for wheeled mobile robots

With the increasing challenges facing planetary exploration missions and the resultant increase in the performance requirements for planetary rovers, terramechanics (wheel–soil interaction mechanics) is playing an important role in the development of these rovers. As an extension of the conventional terramechanics theory for terrestrial vehicles, the terramechanics theory for planetary rovers, which is becoming a new research hotspot, is unique and puts forward many new challenging problems. This paper first discusses the significance of the study of wheel–soil interaction mechanics of planetary rovers and summarizes the differences between planetary rovers and terrestrial vehicles and the problems arising thereof. The application of terramechanics to the development of planetary rovers can be divided into two phases (the R&D phase and exploration phase for rovers) corresponding to the high-fidelity and simplified terramechanics models. This paper also describes the current research status by providing an introduction to classical terramechanics and the experimental, theoretical, and numerical researches on terramechanics for planetary rovers. The application status of the terramechanics for planetary rovers is analyzed from the aspects of rover design, performance evaluation, planetary soil parameter identification, dynamics simulation, mobility control, and path planning. Finally, the key issues for future research are discussed. The current planetary rovers are actually advanced wheeled mobile robots (WMRs), developed employing cutting-edge technologies from different fields. The terramechanics for planetary rovers is expected to present new challenges and applications for WMRs, making it possible to develop WMRs using the concepts of mechanics and dynamics.