Multiple Robot System Research Articles

1P2-S-027 知識ベース拡張進化型群知能ロボットシステムの研究 : 知識の共有による知能の均一化の研究(複数ロボットの協調制御,生活を支援するロボメカ技術のメガインテグレーション)

1P2-S-027 知識ベース拡張進化型群知能ロボットシステムの研究 : 知識の共有による知能の均一化の研究(複数ロボットの協調制御,生活を支援するロボメカ技術のメガインテグレーション)

1P2-S-029 階層型群構造をもったロボットシステムによる協調作業(複数ロボットの協調制御,生活を支援するロボメカ技術のメガインテグレーション)

1P2-S-029 階層型群構造をもったロボットシステムによる協調作業(複数ロボットの協調制御,生活を支援するロボメカ技術のメガインテグレーション)

공동 작업하는 다중 로봇 시스템의 동적 조작도

공동 작업하는 다중 로봇 시스템의 동적 조작도

Real-time cooperative collision avoidance method of multiple mobile robots

In a previous study, the authors have proposed the Cooperative Collision Avoidance (CCA) method. The method extended the Velocity Obstacle to multiple mobile robot systems by introducing the concept of the Common Velocity Obstacle, and achieved cooperative collision avoidance among multiple mobile robot systems without supervisor or communication. The problem of the method was the enormous computation caused by the high dimensional search, and two improved CCA method are introduced in this paper. The first method transforms the search structure from a massive monolithic search into two separate light searches and this leads to significant reduction of the computation from O(a4) to O(a2), where a is the resolution of the search. The second method solves the search analytically by applying an assumption that every robot has a direction oriented objective. The effectiveness of the two methods are confirmed by the computer simulations.

On robot-borne extended object tracking using the em algorithm

High precision tracking of all surrounding objects is a prerequisite to the autononious/senii-autononious management of multiple mobile robot systems. This task comprises not only tracking of moving objects, but also detection of obstacles or other stationary objects. We demonstrate that Expectation-Maximization applied to multiple object tracking is a promising method being flexible enough to handle the problems typical of robot-borne tracking, such as extended objects, dense object environment, mutual occlusions. Observations and preliminary conclusions based on simulated and real sensor data are discussed.

Cooperative Control Algorithm for Object Transportation by Multiple Robot System with a Pushing Leader

Cooperative Control Algorithm for Object Transportation by Multiple Robot System with a Pushing Leader

A geometric approach to single and multiple robot control

This paper describes the control of single and multiple robot teams in the framework of Hilbert spaces. For single robots the control problem is defined in terms of the convergence between the set of feasible velocities, defined by the robot kinematics, and the set of goal velocities, defined by the mission specifications and environment data acquired along the mission. The convergence between these velocity sets is obtained by chosing a set of controls leading to a decrease in the distance between them. This distance is measured through the use of a monotonic and non-expansive projection map.Team control is approached through the definition of neighboring relationships among the teammates, to be preserved along the mission. Each robot monitors these relationships for relevant changes and adapts its motion to the rest of the team according to a negotiation procedure supervised by a finite state automaton. Simulation results on single and multiple cart robot systems are presented.

Solving function distribution and behavior design problem for cooperative object handling by multiple mobile robots

This paper addresses the function distribution and behavior design problem for a multirobot system which incorporates a behavior-based dynamic cooperation strategy for object handling. The proposed multiple robot system is composed of a managing robot and homogeneous behavior-based robots. The cooperation strategy in this system is realized in two steps: designing the distributed robot's cooperative behavioral attributes according to the robot's abilities, and organizing these behavioral attributes so that team cooperation is realized. For indicating an incremental style of local behavior construction, an advanced design of cooperative behavior for coping with unknown disturbance is addressed. Additionally, two extended cooperation strategies designed for a path tracking task are described. These three strategies are based on the same concept on performing manipulation in coordination. Therefore, by considering the function distribution among the managing robot and worker robots, and considering behavior design of each worker robot, the proposed system is able to achieve the object handling task with different performances according to the task requirement, such as with or without path tracking and with or without contact with the environment. Experimental results demonstrate the applicability of the proposed system.

LOGUE: an architecture for task and behavior object transmission among multiple autonomous robots

This paper proposes a new communication and control architecture which improves the capability and the flexibility of multiple autonomous robot systems in performing a complicated task and coping with unpredictable situations. This system treats robot’s information as a Behavior Element Object (BEO) and a Task Object (TO) in terms of Object Oriented paradigm. Both BEO and TO can be serialized, so they can be communicated among the robots and behavior server system in the network. The action manager module, device module, and some checking mechanisms are also designed for executing new TO or BEO sent from other robots or a server system. A simulation and basic experiments are presented for a situation of robots’ relief for an emergency purpose.

Multiple manipulator control from a human motor-control perspective

The human motor-control system has a hierarchical and decentralized structure, and building such a control system for a multiple robot system would require a decomposed model. The difficulty in decomposing complex robotic systems is due to interactions between robots, and the paper proposes a control architecture that controls the manipulator joints and interactions separately. A decomposable model for an N - n degrees-of-freedom multimanipulator/object system handling an object is derived. This model is then used to design a Lyapunov-based fuzzy logic controller for the system by solving linear matrix equalities. It is shown that this controller is closed-loop stable and a stable suboptimal controller for the system may be designed using bounds.

Practical stability of multiple robot manipulators in contact tasks

Practical stability of multiple robots for compliant manipulation on dynamic enviroments is addressed in this paper. The complete dynamic model of multiple robots holding a dynamic object is presented. The control task is specified as a task of practical stability of multiple robots around the nominal robot trajectories. An adaptive control law composed of an identification part (parameter update law), and a control law part is synthesized. It has the inverse dynamics controller structure. The test condition for the practical stability of the multiple robots system with the proposed adaptive control law is derived.

2A1-3F-C5 群ロボットシステムにおける群体の保持と移動に関する研究

2A1-3F-C5 群ロボットシステムにおける群体の保持と移動に関する研究

MACROSCOPIC QUANTITATIVE OBSERVATION OF MULTI-ROBOT BEHAVIOR

In observing behavior of multiple autonomous robots, a microscopic observation expressed by dynamic equations is usually used. However, it is very difficult to estimate behavior of robots or mutual interactions among them in real time. Furthermore, it is hard to realize the observed system by taking consideration in all the factors of the system. On the other hand, a macroscopic observation defined by state equations is efficient for recognizing behavior of multiple robots. In this study, a quantitative observation approach is proposed on behavior of multiple robots. This approach introduces macroscopic state quantities in thermodynamics into expression of the multiple robots system. The advantage of this approach is that observation on the behavior of autonomous robots in real world can be mapped to characteristic quantities in another conceptual state space. At first, the state quantities of multiple robots system are defined and their physical meaning is discussed regarding it as quantitative observation of multiple robots. The macroscopic state quantities in thermodynamics, such as temperature, pressure and entropy, are introduced into mobile robots system. Each mobile robot is regarded as a particle in term of thermodynamic systems. Experiments show that the states of robots system can be classified from a viewpoint of the macroscopic state quantities in thermodynamics. This verifies that the macroscopic quantitative observation is efficient and applicable to controlling multiple robots system.

Human-supervised multiple mobile robot system

In order that robots may achieve tasks in unknown environments, research focusing on the following three points must be conducted: (1) design of commands from the operator to the robots; (2) environmental recognition to show the operator information about the remote work area where robots are working; and (3) interface between a system and the operator and information display of the work area for the operator. For (1), the focus is on the operation of the multiple robots by a single operator. For (2), the problem is divided into two parts; object recognition and self-positioning. As for (3), a graphical user interface is implemented. The operator mainly uses a mouse to input commands, and the operator watches a virtual environment to monitor remote working areas. The virtual environment is constructed with the environment information acquired by the method described in (2) above. After the problems mentioned above are solved, our system will provide a flexible command and monitoring structure and an operator would be able to command the robots appropriately. These are the main advantages of the method we are proposing. We verified the effectiveness of the proposed methods in experiments.

Planning and controlling cooperating robots through distributed impedance

AbstractThis article presents distributed impedance as a new approach for multiple robot system control. In this approach, each cooperating manipulator is controlled by an independent impedance controller. In addition, along selected degrees of freedom, force control is achieved through an external loop, to improve control of the object's internal loading. Extensive stability analysis is performed, based on a realistic model that includes robot impedance and object dynamics. Experiments are performed using two cooperating industrial robots holding an object through point contacts. Force and position control actions are suitably dispatched to achieve both internal loading control and object position control. Individual impedance parameters are specified according to the theoritical stability criterion. The performance of the system is demonstrated for transportation and contact tasks. © 2002 Wiley Periodicals, Inc.

Collision Avoidance System for Multiple Mobile Robots Transporting a Single Object in Coordination Based on Function Allocation Concept.

The decentralized motion control architecture for multiple robots in coordination is a natural extension of human behaviors to robots. Decentralized motion control system for multiple mobile robots transporting a single object in coordination has been proposed and extended to nonholonomic tracked mobile robots driven by two actuators. Systems have an architecture of a leader-follower type, with which the resultant pose of the object is not uniquely determined. In this paper, we propose a new multiple robots system of the leader-followers type based on the function-allocation concept. To illustrate the concept, we developed a leader-follower robot system, in which the leader is in charge of the handling motion of the object and the followers avoid collisions to obstacles and handle the object in coordination with the leader. Experimental results will illustrate the validity of the proposed method.

CONSTRUCTION OF INFRARED WIRELESS INTER-ROBOT COMMUNICATION NETWORKS FOR DISTRIBUTED SENSING AND COOPERATION OF MULTIPLE AUTONOMOUS MOBILE ROBOTS

This paper presents a space-division optical wireless inter-robot communication system for multiple mobile robots. Infrared optical wireless communication is suitable for the mobile robots, because of its low level of interference in multiple directions. However, optical wireless communication is lost when either of the robots runs and/or rotates due to the nature of infrared rays. The proposed communication system has a set of infrared transceivers, which face all directions. The system can maintain circuit connections by exchanging transceivers. Furthermore it can communicate at the same time with more than one robot in different positions by using different transceivers. Spontaneous construction of inter-robot communication networks based on the selection of arbiters is described. As an example of local sensing capabilities of the system, mutual localization using transceivers on three communicating robots is also described. Hardware realization and performance measurements are illustrated to reveal the effectiveness of the proposed system.

Adaptive tracking control for cooperative multiple robot systems

This study presents a novel adaptive controller for cooperative multiple robot systems to obtain both zero motion and force tracking errors. First, by introducing the concepts of force decomposition and virtual control input, we reformulate the control problem of cooperative manipulators as a problem of controlling a single constrained manipulator. Next, a stable subspace is defined by both motion and internal force errors. This subspace includes both zero motion and force errors as its largest invariant set. The controller is then designed to drive the error dynamics into the stable subspace. A non‐adaptive and an adaptive approach both systematically show the asymptotic motion/internal force tracking. Note here that the zero force tracking error is achieved without needing the persistent excitation (PE) condition in the adaptive control scheme. Furthermore, based on a decentralized method, the proposed controllers are implemented in multiprocessor systems to balance the computation load. Finally, two cooperative planar robots are used to demonstrate the developed methodology where the simulation results illustrate the expected performance.

Development of an Environment Recognition System for Multiple Mobile Robots Controlled by a Human

This paper deals with an environmental recognition method for operation of multiple mobile robots. Until now. we have been developing a system for multiple mobile robot operation by a single human user. In order that the user operates multiple robots appropriately. he/she must know information of an environment around the robots. Hence we build a virtual environment and show it to the user. To build the virtual environment. we must solve two problems; object recognition and self-positioning. Concerning the former. the two robots. each equipped with a monocular camera, acquire a 3-dimensional position of a point within an environment with stereovision method. As for the latter. markers are placed on the robots so that their relative positions can be measured. In each phase mentioned above, the human user gives commands to the robots appropriately. After the problems mentioned above are solved. the virtual environment can be constructed with the environmental information. The virtual environment displays remote site information to the user. Experiment shows the effectiveness of the proposed method.

A Space-Division Optical Wireless Inter-Robot Communication System with Mutual Localization Ability for Multiple Autonomous Mobile Robots

This paper presents a space-division optical wireless inter-robot communication system for multiple mobile robots. Infrared optical wireless communication is suitable for the mobile robots, because of its low level of interference in multiple directions. However, optical wireless communication is lost when either of the robots runs and/or rotates due to the nature of infrared rays. The proposed communication system has many infrared transceivers, which face all directions. The system can maintain circuit connections by exchanging transceivers. Furthermore it can communicate at the same time with more than one robot in different positions by using different transceivers. As an example of local sensing capabilities of the system, mutual localization using transceivers on three communicating robots is also described. Hardware realization and performance measurements are illustrated to reveal the effectiveness of the proposed system.