Group Of Mobile Robots Research Articles

Herding by caging: a formation-based motion planning framework for guiding mobile agents

We propose a solution to the problem of herding by caging: given a set of mobile robots (called herders) and a group of moving agents (called sheep), we guide the sheep to a target location without letting them escape from the herders along the way. We model the interaction between the herders and the sheep by defining virtual “repulsive forces” pushing the sheep away from the herders. This enables the herders to partially control the motion of the sheep. We formalize this behavior topologically by applying the notion of caging, a concept used in robotic manipulation. We demonstrate that our approach is provably correct in the sense that the sheep cannot escape from the robots under our assumed motion model. We propose an RRT-based path planning algorithm for herding by caging, demonstrate its probabilistic completeness, and evaluate it in simulations as well as on a group of real mobile robots.

Controlling the movement of a group of mobile robots in a column

The work solves the problem of managing a team of robots, which ensures the movement of a team of robots in a column. Management is carried out using an alternative collective adaptation algorithm based on the ideas of the collective behavior of adaptation objects. To implement the adaptation mechanism, the parameters of the vector are compared to the adaptation automata, a, which simulate the behavior of adaptation objects in the environment. The structure of the process of alternative collective adaptation has been developed, under the control of which the movement of a group of robots in a formation is carried out.

Toward Emerging Cubic-Spline Patterns With a Mobile Robotics Swarm System

An innovative and flexible approach is introduced to address the challenge of self-organizing a group of mobile robots into cubic-spline-based patterns without any requirement of control points. Besides the self-organization of mobile robots, the approach incorporates a potential field-based control for obstacle/collision avoidance. This will offer more flexibility to swarm robots to efficiently deal with many practical situations, including smoothly avoiding obstacles during movement or exploring and covering areas with complex curved patterns. Essentially, this challenge is approached by proposing a formation control model based on a smoothed particle hydrodynamic estimation technique, which uses special cubic-spline kernel functions applied here to interpolate the density of each robot in the swarm. The moving information is used to weigh the distances to the robot’s neighbors available in its field of view. Then, an artificial physics mesh is finally built among each robot and its three available neighbors having the smallest weighted distances. Significant results toward emerging cubic-spline patterns are shown with a swarm of foot-bot mobile robots simulated in the ARGoS platform. Analysis results with different metrics are also conducted to assess the performance of the model with different swarm sizes and in the presence of sensory noise as well in the presence of partially faulty robots.

Formation Control of Stochastic Multivehicle Systems

In this article, we propose a decentralized approach to formation control in groups of stochastic mobile robots. Different from existing work, we explicitly model the presence of stochastic perturbations affecting the dynamics and model the multivehicle system through stochastic differential equations. We design a decentralized formation control strategy where only a subset of informed agents is aware of the desired target locations and derive sufficient conditions for almost sure convergence to the desired formation pattern. Specifically, we illustrate how the achievement of the control goal is related to the intensity of the noise and to the topology of the communication graph among the robots. The proposed formation control strategy is tested through extensive numerical analyses and validated experimentally on ground robots.

ІНТЕГРАЦІЯ ШТУЧНОГО ІНТЕЛЕКТУ В БІЗНЕС ПРОЦЕСИ

AI performs many tasks, including - creating and working in symbolic computing systems, creating and working in systems with fuzzy logic, cognitive psychology, understanding natural language, creating expert systems, computer linguistics, automation of various vocabulary and lexical cards, behavior planning (search and proposal of the most optimal way to achieve the goal, based on this situation), machine translation, creation and management of intelligent robots and groups of mobile robots, etc.

A Comparison of Different Approaches for Formation Control of Nonholonomic Mobile Robots regarding Object Transport

Controlling the formation of several mobile robots allows for the connection of these robots to a large virtual unit. This enables a group of mobile robots to carry out tasks that a single robot could not perform. For this purpose, the use of nonholonomic mobile robots is especially useful, as they often have a higher payload and are suitable for a wider range of terrains. However, most research in the area of formation control is focused on holonomic robots, since their superior mobility allows for better control and allows for the research on more sophisticated control techniques. The remaining articles explicitly dealing with nonholonomic robots often do cover common controllers, but do not include realistic simulations or comparison of different controls on the same trajectory. Therefore, in this paper, we present a comparative analysis of two frequently used control approaches. We compare the behavior of a l-ψ-controller and a Cartesian reference-based controller with different types of reference value generation and pose determination. The evaluation of all resulting control schemes is based on the task of collaborative object transport. To do so, we selected performance criteria geared towards applicability in real processes. In addition, we used an error model, which takes into account the noise and accuracy of all sensors (IMU and encoder) as well as the drift in odometry caused by the slip of the robot’s wheels. The comparison includes a series of simulations using two trajectories with a changing number of robots and different formation geometries. In the simulations we got slightly better results for the Cartesian control law.

МОДЕЛИ И МЕТОДЫ ПРОЕКТИРОВАНИЯ ДИНАМИЧЕСКИ РЕКОНФИГУРИРУЕМОЙ СИСТЕМЫ ГРУППОВОГО УПРАВЛЕНИЯ МОБИЛЬНЫМИ РОБОТАМИ

High adaptability is an important requirement for the control system over a group of mobile robots operating in a nondeterministic changing environment. The group control system must ensure that the group task is completed when the structure of the group or the environment changes. Such adaptability can be achieved through dynamic reconfiguration of the control system. The article discusses the mathematical models of a dynamically reconfigurable system from the standpoint of computer-aided design. A review of mathematical models of variable structure system, reconfigurable control systems and their design methods is presented. The paper deals with set-theoretic, analytical, discrete-event models of variable structure systems and methodologies of designing reconfigurable systems. It is shown that the existing design methods do not fully provide the required adaptability of designed group control system. The paper compares the group control system and the reconfigurable multiprocessor computing system and shows how to increase adaptability and autonomy of designed control system using principles of reconfigurable computing systems designing.

Comparative study of numerical solutions for the optimal control problem in the presence of uncertainties

The numerical solution of the optimal control problem is addressed. In the paper we compare a new approach of synthesized optimal control with one of the direct approach to solve a control problem for a group of mobile robots in the complex environment with phase constraints in the presence of noise and uncertainties in model and initial conditions. It is shown in the paper that the approach based on stabilization of the system is much less sensitive to different perturbations.

Выявление неисправностей в группах мобильных роботов с использованием скользящих наблюдателей

The paper studies the emerging trends in advanced computing and information technology for efficient solutions of fault identification problem for mobile robot groups under the unmatched disturbances. The sliding mode observers are considered for mentioned problem solution. It facilitates the concept of Smart everything inside the considered robotic group during its generalized control: smart surrounding sensing, communication, processing, and scanned data storing. The suggested novel approach to sliding mode observer design is based on obtaining the reduced order model of the initial system. This allows reduce the complexity of sliding mode observer and relax restrictions imposed on the initial system.

A protocol for organizing a decentralized wireless communication network for ensuring the interaction of a group of intelligent mobile robots

A protocol for organizing a decentralized wireless communication network for ensuring the interaction of a group of intelligent mobile robots

Effective Dynamic Coverage Control for Heterogeneous Driftless Control Affine Systems

To dynamically monitor areas of interest by a group of mobile robots, an effective coverage control strategy for heterogeneous driftless control affine systems is developed in this letter. The coverage strategy guides the robot to move in the direction of the effective coverage and escape the saddle point when the loss function stops descending. In addition, the connectivity of the underlying communication network of the robots is maintained during coverage control. Simulation validates the effectiveness of our proposed coverage strategy.

Fault Identification in Mobile Robot Groups Using Sliding Mode Observers

The paper studies the emerging trends in advanced computing and information technology for efficient solutions of fault identification problem for mobile robot groups under the unmatched disturbances. The sliding mode observers are considered for mentioned problem solution. It facilitates the concept of Smart everything inside the considered robotic group during its generalized control: smart surrounding sensing, communication, processing, and scanned data storing. The suggested novel approach to sliding mode observer design is based on obtaining the reduced order model of the initial system. This allows reduce the complexity of sliding mode observer and relax restrictions imposed on the initial system.

Fixed-time trajectory tracking control for multiple nonholonomic mobile robots

This paper investigates the fixed-time trajectory tracking control for a group of nonholonomic mobile robots, where the desired trajectory is generated by a virtual leader, the leader’s information is available to only a subset of the followers, and the followers are assumed to have only local interaction. According to fixed-time control theory and adding a power integrator technique, distributed fixed-time tracking controllers are developed for each robot such that all states of each robot can reach the desired value in a fixed time. Moreover, the settling time is independent of the system initial conditions and only determined by the controller parameters. Simulation results illustrate and verify the effectiveness of the proposed schemes.

3D Optical Machine Vision Sensors With Intelligent Data Management for Robotic Swarm Navigation Improvement

The optimized communication within robotic swarm, or group (RG) in a tightly obstacled ambient is crucial point to optimize group navigation for efficient sector trespass and monitoring. In the present work the main set of problems for multi-objective optimization in a non-stationary environment is described. It is presented the algorithm of data transfer from 3D optical sensor, based on the principle of dynamic triangulation. It uses the distributed scalable big data storage and artificial intelligence in automated 3D metrology. Two different simulations in order to optimize the fused data base for better path planning aiming the improvement of electric wheeled mobile robots group navigation in unknown cluttered terrain is presented. The optical laser scanning sensor combined with Intelligent Data Management permits more efficient dead-reckoning of the RG.

STPA and Bowtie risk analysis study for centralized and hierarchical control architectures comparison

The industrial zones are increasingly invaded by groups of mobile robots that are the most capable to perform complex tasks by collaborating and cooperating together. The operation of a mobile robot within a dynamic and high-risk environment with strong interaction between robot-robot and human-robot is of a certain complexity of control and safety. Such type of systems requires a safety and hazard investigation to verify if it is able to operate under certain operating conditions, while still ensuring the control and collaboration between mobile robots and human. This paper presents an approach that combines aspects of System-Theoretic Process Analysis (STPA) and Bowtie for safety assessment purposes. The approach we propose is used for a case related to multi-robot systems considering the coordinating, cooperating and collaborating aspects. At first, a risk identification study is done using STPA to extract a set of risk scenarios related to different types of hierarchical coordination architectures in addition to their factors. Afterward, an evaluation of the obtained scenarios is performed by the Bowtie method. The aim of our study is to better compare different control approaches of a multi-agent system. The combination offers detailed hazard identification. It further provides a classification of risks which helps to improve STPA outcomes thus facilitate decision-making over the suitable approach.

Laser Pouch Motors: Selective and Wireless Activation of Soft Actuators by Laser-Powered Liquid-to-Gas Phase Change

Untethered control of soft-bodied robots is attractive for interactions in a variety of unstructured and dynamic environments. However, soft robotics systems are currently limited in terms of wireless, selective, and scalable control of multiple actuators. Therefore, we propose a method to wirelessly drive multiple soft actuators by laser projection. A small amount of low-boiling-point liquid inside a planar thin pouch can be heated by a laser and evaporated to inflate the whole body. Laser projection enables both wireless energy supply and the selection of target actuators. Further, the low-boiling-point liquid serves as an actuation source and as a receiver of laser irradiation. Thus, we do not need additional components such as electric circuits and batteries to achieve simple and scalable implementation of multiple soft actuators. We evaluated the mechanical properties and demonstrated that the system can wirelessly control the gestures of fingers of a robot hand. We also verified that our method can activate a group of mobile soft robots simultaneously and individually while tracking the actuator positions. Our approach contributes to the scalable deployment of soft robotic systems by removing tethers for power and communication.

Design and Experimental Validation of a Distributed Cooperative Transportation Scheme

Leveraging explicit communication and cooperation of multiple robots brings about multiple advantages in the solution of tasks with autonomous robotic agents. For this reason, to the end of transporting polygonal objects with a group of mobile robots, the aim of this article is to develop a fully distributed decision-making and control scheme that lets the robots cooperate as equals, without any kind of central control instance. Apart from coordinating the motions of the robots in a distributed manner, challenges include the self-reliant determination of configurations of the robots around the object, as well as the interrobot negotiation on which robot takes which role or position in the transportation process. Based on some assumptions on the properties of the robots and the considered types of objects, all major aspects of the control scheme are explained in detail, with the most crucial parts making use of optimization-based schemes. This enables unprecedented flexibility by letting the robots automatically adapt to a wide range of scenarios, with different numbers of robots cooperating, and accommodating intricate object shapes. A simulation-based analysis reveals some of the key properties of the proposed scheme, whereas hardware-in-the-loop experiments show the practical applicability with inexpensive hardware. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —This article was motivated by the potential to further the state of the art of what is possible to achieve with autonomous robots when, instead of using one single robot, a group of robots cooperates self-reliantly to solve a task. The scenario studied in this article is a transportation task in which the robots shall cooperatively push an object to transport it along the desired path. The scheme proposed in this article deals with all major aspects of solving this transportation task, with simulations and hardware-in-the-loop experiments showing the practical applicability of the scheme. While the experiments have been conducted in a laboratory environment, one may readily imagine a more productive application, e.g., in logistics, when employing suitably designed hardware. On another note, maybe more importantly, the general architecture devised to solve the present task may serve as an inspiration or blueprint for the development of decision-making and control schemes that deal with alternative cooperative robotic tasks, especially with regard to the usage of optimization-based schemes on multiple levels allowing a flexible, yet still intuitive problem formulation.

Security methods for a group of mobile robots according to the requirements of Russian and foreign legislation

This paper is devoted to the problem of creating security methods for mobile robotic systems. The urgency of the problem of ensuring the security of mobile robotic systems is associated with the presence of a contradiction between the growing popularity of the mobile robotic systems and the presence of many vulnerabilities. Development of a universal security system which should provide protection not only against an malicious attack, but also allow the system to cope with unintentional errors, interference or changes in the external environment, thereby improving the operation of group control algorithms for robots, and increasing the reliability and stability of the mobile robotic systems.

Self-Adaptation of a Heterogeneous Swarm of Mobile Robots to a Covered Area

An original swarm-based method for coordination of groups of mobile robots with a focus on the self-organization and self-adaptation of the groups is presented in this paper. The method is a nature-inspired decentralized algorithm that uses artificial pheromone marks and enables the cooperation of different types of independent reactive agents that operate in the air, on the ground, or in the water. The advantages of our solution include scalability, adaptability, and robustness. The algorithm worked with variable numbers of agents in the groups. It was resistant against failures of the individual robots. A transportation control algorithm that ensured the spreading of different types of agents across exploration space with different types of environments was introduced and tested. We established that our swarm control algorithm was able to successfully control three basic behaviors: space exploration, population management, and transportation. The behaviors were able to run simultaneously, and space exploration (the main goal) was never stopped or interrupted. All these features combined in a single algorithmic package represent a framework for future development of swarm-based agent systems applicable in a broad scope of environments. The results confirmed that the algorithm can be applied to monitoring, surveillance, patrolling, or search and rescue tasks.

The Control System for a Group of Mobile Robots from the Perspectives of Automated Designing

The Control System for a Group of Mobile Robots from the Perspectives of Automated Designing