Cooperative Mobile Robots Research Articles

2P1-G07 限定的通信手法と強化学習を用いた移動ロボット群のため協調行動獲得方法

When a robot moves, there should be a lot of information processing underlying o cope with an uncertain environment, especially in cases where many different mobile robots exist. Sensors such as cameras and laser range finders are needed to recognize the environment. But such accurate devices are expensive. By this reason, a short range telecommunication protocol that is simple and inexpensive is needed. This paper is to study a design of co-operative mobile robots in real environment by proposing a telecommunication system that is simple and cheap but acting sufficiently to maintain co-operative behaviors. The idea is to send a robot's "conviction level" with each other and accelerates to prioritize" experienced robots" to gain rapid congestion resolution. The robot learns this behavior by using the conviction level. Action acquisition experiment was done by using the propsed system. The results show the paper actions were learned through this system.

Communication Timing Control and Topology Reconfiguration of a Sink-Free Meshed Sensor Network With Mobile Robots

This paper deals with a unified system of fully distributed meshed sensor network and mobile robot cooperation that serves as a sink node. The meshed sensor network in this paper is composed of static wireless nodes, and is capable of fully distributed peer-to-peer (P2P) <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">hoc</i> communication with ZigBee-based protocol. A novel communication timing control employing coupled-oscillator dynamics, named phase-diffusion time-division method (PDTD), has been proposed so far, aiming at realization of an <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">hoc</i> collision-free wireless communication network. In this paper, we extend the basic PDTD so that it can exhibit flexible topological reconfiguration according to the moving sink node (robot). Unlike conventional sensor network, no static sink node is supposed inside the network; however, a mobile robot will function as a sink node and access the mesh network from an arbitrary position. A large-scale experiment was conducted, and its results show that satisfactory collaboration between the mesh sensor network and the mobile robot is achieved, and the proposed system outperformed the carrier-sense-multiple-access-based sensor system.

2A1-B22 通信タイミング制御とトポロジー再構成を行うシンクフリーメッシュセンサネットワーク

This paper deals with a unified system of fully distributed meshed sensor network and mobile robot cooperation which serves as a sink node. A novel communication timing control employing coupled-oscillator dynamics, named Phase Diffusion Time Division method (PDTD) has been proposed so far, aiming at realization of ad-hoc collision free wireless communication network. In this paper, We extend the basic PDTD so that it can exhibit flexible topological reconfiguration according to the moving sink node(robot). Unlike conventional sensor network, no static sink node is supposed inside the network, however a mobile robot will function as a sink node and access to the mesh network from an arbitrary position. Large scale experiment was conducted and its results show that satisfactory collaboration between the mesh sensor network and the mobile robot is achieved, a≪d the proposed system outperformed CSMA-based sensor network system.

Communication Timing Control and Topology Reconfiguration of a Sink-Free Meshed Sensor Network With Mobile Robots

This paper deals with a unified system of fully distributed meshed sensor network and mobile robot cooperation that serves as a sink node. The meshed sensor network in this paper is composed of static wireless nodes, and is capable of fully distributed peer-to-peer (P2P) <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">hoc</i> communication with ZigBee-based protocol. A novel communication timing control employing coupled-oscillator dynamics, named phase-diffusion time-division method (PDTD), has been proposed so far, aiming at realization of an <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">hoc</i> collision-free wireless communication network. In this paper, we extend the basic PDTD so that it can exhibit flexible topological reconfiguration according to the moving sink node (robot). Unlike conventional sensor network, no static sink node is supposed inside the network; however, a mobile robot will function as a sink node and access the mesh network from an arbitrary position. A large-scale experiment was conducted, and its results show that satisfactory collaboration between the mesh sensor network and the mobile robot is achieved, and the proposed system outperformed the carrier-sense-multiple-access-based sensor system.

Collision Prevention Platform for a Dynamic Group of Asynchronous Cooperative Mobile Robots

This paper presents a fail-safe platform on which cooperative mobile robots rely for their motion. The platform consists of a collision prevention protocol for a dynamic group of cooperative mobile robots with asynchronous communications. The collision prevention protocol is timefree, in the sense that it never relies on physical time, which makes it extremely robust for timing uncertainty common in wireless networks. It guarantees that no two robots ever collide, regardless of the respective activities of the robots. The protocol is based on a fully distributed path reservation system. It assumes a mobile ad hoc network formed by the robots themselves, and takes advantage of the inherent locality of the problem in order to reduce communication. The protocol requires neither initial nor complete knowledge of the composition of the group. A performance analysis of the protocol provides insights for a proper dimensioning of system parameters in order to maximize the average effective speed of the robots.

Adaptive and cooperative mobile robots

This paper focuses on the development of intelligent multiagent robot teams capable of acting autonomously and of collaborating in a dynamic environment to reach team objectives. The paper proposes a new adaptive action selection architecture that enables a team of robot agents to achieve adaptive cooperative control and modify their performance during the specified time of the mission. These abilities are important because of uncertainty in the environmental conditions and because of possible functional failures in some team members. The improvement in team performance is achieved by updating the control parameters of the robots based on knowledge acquired on-line. Experiments have been conducted on teams of mobile robots performing a cooperative box-pushing task. The results show that the robot teams were able to achieve adaptive cooperative control despite dynamic changes in the environment and variations in the capabilities of the team members.

Development of multiple robotic fish cooperation platform

This article presents the development of a multiple robotic fish cooperation platform, which is established by employing a group of radio-controlled, multi-link fish-like robots. This work is inspired by the observation from nature that the capability of one single fish is limited, as in order to survive the atrocious circumstances in the sea, fish often swim in schools. The analogical situations occur in the robotic fish case. In engineering applications, most missions are so complex that they must be accomplished by effective cooperation of multiple fish robots. The platform presented in this article, as a novel test bed for multiple robotic fish cooperation, can be applied to different types of complex tasks. More importantly, it provides a good platform to test and verify all kinds of algorithms and strategies for cooperation of multiple underwater mobile robots. We use two cooperative tasks as examples to heuristically demonstrate the performance of this platform.

Mobile robotic sensors for perimeter detection and tracking

Mobile robot/sensor networks have emerged as tools for environmental monitoring, search and rescue, exploration and mapping, evaluation of civil infrastructure, and military operations. These networks consist of many sensors each equipped with embedded processors, wireless communication, and motion capabilities. This paper describes a cooperative mobile robot network capable of detecting and tracking a perimeter defined by a certain substance (e.g., a chemical spill) in the environment. Specifically, the contributions of this paper are twofold: (i) a library of simple reactive motion control algorithms and (ii) a coordination mechanism for effectively carrying out perimeter-sensing missions. The decentralized nature of the methodology implemented could potentially allow the network to scale to many sensors and to reconfigure when adding/deleting sensors. Extensive simulation results and experiments verify the validity of the proposed cooperative control scheme.

Sociable Robots Through Self-Maintained Energy

Research of autonomous mobile robots has mostly emphasized interaction and coordination that are natually inspired from biological behavior of birds, insects, and fish: flocking, foraging, collecting, and sharing. However, most research has been only focused on autonomous behaviors in order to perform robots like animals, whereas it is lacked of determinant to those behaviours: energy. Approaching to clusted amimal and the higher, collective and sharing food among individuals are major activity to keep society being. This paper issues an approach to sociable robots using self-maintained energy in cooperative mobile robots, which is dominantly inspired from swarm behavior of collecting and sharing food of honey-bee and ant. Autonomous mobile robots are usually equipped with a finite energy, thus they can operate in a finite time. To overcome the finitude, we describe practical deployment of mobile robots that are capable of carrying and exchanging fuel to other robots. Mechanism implementation including modular hardware and control architecture to demonstrate the capabicities of the approach is presented. Subsequently, the battery exchange algorithm basically based on probabilistic modeling of total energy on each robot located in its local vicinity is described. The paper is concluded with challenging works of chain of mobile robots, rescue, repair, and relation of heterogeneous robots.

TEAM FORMATION BASED ON NONLINEAR CONTROL TECHNIQUES AND OMNIDIRECTIONAL VISION

In this work a mobile robot cooperation strategy based on computational vision is presented. Such strategy is applied to a mobile robot team formed by simple and cheap robots and a leader robot with more computational power. The leader has an omnidirectional visual system and uses color segmentation to obtain the pose of the followers. This visual information is used by a nonlinear stable controller that manages team formation. Simulations and tests were run and current results are encouraging.

ロボットと時空間GISの連携による段階的な震災データ収集システムの開発

ロボットと時空間GISの連携による段階的な震災データ収集システムの開発

Model predictive disturbance rejection during cooperative mobile robot assembly tasks

This paper addresses the problem of disturbance compensation for the successful assembly of structures by mobile field robots. A control architecture, consisting of a linear PID joint controller with model predictive feed-forward compensation for mobile base motions and interactive-force disturbance rejection is discussed. Object insertion is achieved by predicting environment-object contact states and motions are planned in the direction of least resistance. Issues addressed include dynamic modeling of multiple cooperative robots, control architecture design and stability analysis, and environment-object contact state prediction. Simulation results show the effectiveness of the control architecture.

Communication system for cooperative mobile robots using ad-hoc networks

This paper presents a distributed, master-less communication system currently used for communication in a fleet of heterogeneous unmanned aerial vehicles in the European project COMETS for wired and wireless links. Communication is realized using distributed shared memory (DSM) where each network node is holding full or part of the DSM. The coherency of the DSM is kept by a real-time aware protocol that provides quality of service guarantee and dynamic routing. Furthermore, an experiment is presented using the communication system on a wireless ad-hoc network.

A multiagent cooperative mobile robotics approach for search and rescue missions

This paper presents a reusable framework for coordinating a team of mobile robots that can accomplish high level or tightly coupled missions, which could not be easily achieved using single robot solutions. To complete this task, we consider the behavior-based architecture model for the basic control layer. For coordinating the team of autonomous mobile robots, we use the agent-oriented software engineering paradigm. We apply the combination of a single and of multiagent techniques for evaluating a search-and-rescue mission. The experiments are using the Pioneer 2 DX robot and the Saphira simulator.

Dynamic mutual calibration and view planning for cooperative mobile robots with panoramic virtual stereo vision

This paper presents a panoramic virtual stereo vision approach to the problem of detecting and localizing multiple moving objects (e.g., humans) in an indoor scene. Two panoramic cameras, residing on different mobile platforms, compose a virtual stereo sensor with a flexible baseline. A novel “mutual calibration” algorithm is proposed, where panoramic cameras on two cooperative moving platforms are dynamically calibrated by looking at each other. A detailed numerical analysis of the error characteristics of the panoramic virtual stereo vision (mutual calibration error, stereo matching error, and triangulation error) is given to derive rules for optimal view planning. Experimental results are discussed for detecting and localizing multiple humans in motion using two cooperative robot platforms.

Distributed Lazy Q-Learning for Cooperative Mobile Robots

Compared to single robot learning, cooperative learning adds the challenge of a much larger search space (combined individual search spaces), awareness of other team members, and also the synthesis of the individual behaviors with respect to the task given to the group. Over the years, reinforcement learning has emerged as the main learning approach in autonomous robotics, and lazy learning has become the leading bias, allowing the reduction of the time required by an experiment to the time needed to test the learned behavior performance. These two approaches have been combined together in what is now called lazy Q-learning, a very efficient single robot learning paradigm. We propose a derivation of this learning to team of robots : the «pessimistic» algorithm able to compute for each team member a lower bound of the utility of executing an action in a given situation. We use the cooperative multi-robot observation of multiple moving targets (CMOMMT) application as an illustrative example, and study the efficiency of the Pessimistic Algorithm in its task of inducing learning of cooperation.

Adaptive Desired Velocity Field Control for Cooperative Mobile Robotic Systems with Decentralized PVFC

Passive velocity field control (PVFC) was previously developed for mechanical systems which have strong coordination and must interact with the physical environment. Moreover, In our previous researches, the extended PVFC algorithm for multiple manipulator systems is also introduced. The methodology of PVFC and extended PVFC encode tasks using time invariant desired velocity fields instead of the more traditional method of time trajectories and guarantees that the closed loop system behave passively with environment power as the supply rate. This paper addresses an adaptive generation method of the desired velocity field for cooperative mobile robots with decentralized PVFC. Of course, this paper is a method of decentralized control algorithm for cooperative mobile robot systems handling a common object in a coordinated way. The proposed control method for cooperative mobile robots in constructed based on the extended PVFC in this paper. Moreover the stability and the boundedness are ensured using projection algorithm. Finally the effectiveness of proposed control method is examined by numerical simulation for cooperation tasks with two 3-wheeled mobile robot systems to consider our previous research.

Behavior Evolution of Autonomous Mobile Robot(AMR) using Genetic Programming Based on Evolvable Hardware

This paper presents a genetic programming based evolutionary strategy for on-line adaptive learnable evolvable hardware. Genetic programming can be useful control method for evolvable hardware for its unique tree structured chromosome. However it is difficult to represent tree structured chromosome on hardware, and it is difficult to use crossover operator on hardware. Therefore, genetic programming is not so popular as genetic algorithms in evolvable hardware community in spite of its possible strength. We propose a chromosome representation methods and a hardware implementation method that can be helpful to this situation. Our method uses context switchable identical block structure to implement genetic tree on evolvable hardware. We composed an evolutionary strategy for evolvable hardware by combining proposed method with other's striking research results. Proposed method is applied to the autonomous mobile robots cooperation problem to verify its usefulness.

2P2-I07 複数ロボット協調動作のための位置と動作タイミングの同期法

複数の移動ロボットを協調させて動作させる場合, それぞれのロボット間で動作のタイミングを合わせることと動作を行う位置の基準を合わせることが重要である。各ロボットに搭載した超音波センサで環境を観測し, ロボット間の観測結果の違いからロボット間の位置のずれを推定し自動的に修正する。また, 同期した時計をそれぞれのロボットに搭載し, 時刻で動作タイミングを指示することでロボット間で動作のタイミングを同期する。講演ではこれらを実装し, 簡易に動作を記述できるシステムについて述べる。

Decentralized PVFC for Cooperative Mobile Robots

Decentralized PVFC for Cooperative Mobile Robots