Center-configuration selection technique for the reconfigurable modular robot

The reconfigurable modular robot has an enormous amount of configurations to adapt to various environments and tasks. It greatly increases the complexity of configuration research in that the possible configuration number of the reconfigurable modular robot grows exponentially with the increase of module number. Being the initial configuration or the basic configuration of the reconfigurable robot, the center-configuration plays a crucial role in system’s actual applications. In this paper, a novel center-configuration selection technique has been proposed for reconfigurable modular robots. Based on the similarities between configurations’ transformation and graph theory, configuration network has been applied in the modeling and analyzing of these configurations. Configuration adjacency matrix, reconfirmation cost matrix, and center-configuration coefficient have been defined for the configuration network correspondingly. Being similar to the center-location problem, the center configuration has been selected according to the largest center-configuration coefficient. As an example of the reconfigurable robotic system, AMOEBA-I, a three-module reconfigurable robot with nine configurations which was developed in Shenyang Institute of Automation (SIA), Chinese Academy of Sciences (CAS), has been introduced briefly. According to the numerical simulation result, the center-configuration coefficients for these nine configurations have been calculated and compared to validate this technique. Lastly, a center-configuration selection example is provided with consideration of the adjacent configurations. The center-configuration selection technique proposed in this paper is also available to other reconfigurable modular robots. Supported in part by the National High-Technology 863 Program (Grant No. 2001AA422360), the Chinese Academy of Sciences Advanced Manufacturing Technology R&D Base Fund (Grant Nos. A050104 and F050108), and the GUCAS-BHP Billiton Scholarship     

Network-based reconfiguration routes for a self-reconfigurable robot

This paper presents a network-based analysis approach for the reconfiguration problem of a self-reconfigurable robot. The self-reconfigurable modular robot named ＂AMOEBA-I＂ has nine kinds of non-isomorphic configurations that consist of a configuration network. Each configuration of the robot is defined to be a node in the weighted and directed configuration network. The transformation from one configuration to another is represented by a directed path with nonnegative weight. Graph theory is applied in the reconfiguration analysis, where reconfiguration route, reconfigurable matrix and route matrix are defined according to the topological information of these configurations. Algorithms in graph theory have been used in enumerating the available reconfiguration routes and deciding the best reconfiguration route. Numerical analysis and experimental simulation results prove the validity of the approach proposed in this paper. And it is potentially suitable for other self-reconfigurable robots＇ configuration control and reconfiguration planning.     

A lattice-type reconfigurable robotic system for achieving gaits of chain-type robots

Traditional lattice-type reconfigurable robots can only achieve the flow-style locomotion with low efficiency. Since gaits of chain-type robots are proved to be efficient and practical, this paper presents a novel lattice distortion approach for lattice-type reconfigurable robots to achieve locomotion gaits of chain-type robots. Using this approach, the robotic system can be actuated by local lattice distortion to move as an ensemble. In this paper, a rule that makes the lattice distortion equivalent to joint rotation is presented firstly. Then, a kind of module structure is designed according to requirements of the lattice distortion. Finally, a motion planning for achieving locomotion is developed, which works well in physics-based simulations of completing a serpentine locomotion gait of a snake-like robot and a tripod gait of a hexapod robot.     

基于JBits的一种可重构数据处理系统可靠性研究

空间太阳望远镜(SST)是一颗对太阳进行观测的科学卫星,它使用FPGA芯片对每天采集的大量数据进行预处理.高昂的建造费用和恶劣的工作环境,确保SST数据的高可靠性成为一项艰巨任务.改进了常规TMR结构,提出一种基于配置数据的可重构硬件故障检测和修复方法,使用JBits工具简化对配置数据的各种操作.此结构和方法能及时检测到故障,通过硬件重构消除故障,提高系统可靠性.采用Markov过程理论对系统可靠性进行分析,结果表明可靠性可得到显著提高.     

Computer architecture for intelligent robots

This article proposes a computer architecture suitable for intelligent robots, especially for self-contained intelligent mobile robots. The main principles proposed by the authors are: (1) The robot should be a multiprocessor system with a master, several slave modules and a console. A simple star connection is employed. (2) The master carries user's programs written in a high level language with which a programmer is able to use all basic functions in the robots. It should have a special purpose operating system. (3) Each module is an independent microcomputer system loosely coupled to the master and dedicated to an elementary function such as manipulation, locomotion, sensing, or planning. (4) A serial TTL level or RS232C interface is employed between the master and each module. Two self-contained robots, Yamabico 9 and 10, constructed under these design principles have demonstrated the effectiveness of this proposed architecture.     

Reconfiguration Planning for a Robotic Vehicle with Actively Articulated Suspension in Obstacle Terrain during Straight Motion

In this paper, an actively articulated suspension (AAS) reconfiguration method is proposed for a robotic vehicle with AAS to negotiate an obstacle during straight motion. Proposed method includes AAS locomotion for the locomotion with the AAS and a calculation method that is independent to the terrain model for posture control using the AAS reconfiguration. Using simulations, it was verified that the proposed method can reconfigure the AAS for a robotic vehicle to have the desired position and posture to negotiate an obstacle. The errors of height and orientation can be reduced while wheel driving on rough terrain. Also, the robot can maintain a minimum static stability angle over 0.6?rad. When observing the obstacle negotiation procedure using the AAS reconfiguration including the proposed locomotion, it was found that the robot can conduct a high-level command successfully using the proposed method. The robot can negotiate an obstacle with a height of 71% of its usable length and can maintain the minimum static stability over 0.3?rad. Also, the robot can manage terrain uncertainty using the proposed AAS reconfiguration method.     

Task-based optimization of reconfigurable robot manipulators

Reconfigurable Manipulators are structurally redundant robots that utilize a subset of their joints to perform a specific task optimally. This paper presents a method of finding a task-based optimal configuration for a new type of reconfigurable robot manipulator, called the modular autonomously reconfigurable serial (MARS) manipulator. The reconfiguration optimization treats the joint space of the MARS manipulator as a 12-dimensional smooth configuration manifold. The manifold is discretized and ranked based on a variety of criteria, and then clustered into attractive and repellent regions. The user then specifies which regions are desired in the target configuration, and the manifold is reduced in dimension in order to maximize the number of attractive regions and minimize the number of repellent regions. Six manipulator configurations are synthesized using this approach, and their effectiveness is compared.     

Continuity aspects of embedded reconfigurable computing

In embedded systems, dynamically reconfigurable computing can be partially modified at runtime without stopping the operation of the whole system. In this paper, we consider a reorganization mechanism for dynamically reconfigurable computing in embedded systems to guarantee that invariants of the design are respected. This reorganization is considered as a visual transformation of the logical configuration by the formulated rules. The invariant is recognized under the restructuring of the configuration using reconfiguration rules.     

Graph-based optimal reconfiguration planning for self-reconfigurable robots

The goal of optimal reconfiguration planning (ORP) is to find a shortest reconfiguration sequence to transform a modular and reconfigurable robot from an arbitrary configuration into another. This paper investigates this challenging problem for chain-type robots based on graph representations and presents a series of theoretical results: (1) a formal proof that this is an NP-complete problem, (2) a reconfiguration planning algorithm called MDCOP which generates the optimal graph-based reconfiguration plan, and (3) another algorithm called GreedyCM which can find a near-optimal solution in polynomial time. Experimental and statistical results demonstrate that the solutions found by GreedyCM are indeed near-optimal and the approach is computationally feasible for large-scale robots.     

模块化机器人拓扑重构规划研究

模块化可重构机器人由若干个相同的机器人模块组合装配而成,能够重构成不同的几何形态和结构,从而适应不同的作业任务要求。本论文主要对树状拓扑结构的模块化机器人的重构规划问题进行了研究,定义了构型重构的基本概念,提出了分支重构规划算法。这类模块化可重构机器人可以用树状拓扑结构图来描述。机器人的拓扑结构从自由树转化为有根树,然后分解为若干个分支结构,并按一定顺序排列,通过对各个分支结构的逐步比较和操作,完成重构过程。最后选定模块数目,进行了重构规划过程的仿真计算。结果表明,文中所述算法对于树状拓扑结构的模块化机器人的重构规划问题是有效的。     

模块化可重构机器人动力学研究进展

模块化可重构机器人由于其构型多变,运动形式丰富等特点,可以在非结构化环境或未知环境中执行任务,在最近几年迅速成为机器人研究领域的前沿和热点. 模块化可重构机器人在军事、医疗、教育等众多工程领域具有广泛的应用前景,其典型代表包括仿生多足模块化机器人、模块化可重构机械臂、晶格式模块化机器人等. 模块化可重构机器人丰富的构型设计、多样的连接特征、不断拓展的应用范围,给动力学建模与控制带来了很多挑战和机遇. 本文首先阐述了模块化可重构机器人的研究背景和意义,并概述了其构型分类与设计、构型描述与运动学建模方法.随后,本文系统回顾了模块化可重构机器人动力学研究中相关问题的最新进展,包括：(1)系统整体动力学建模;(2)结合面以及对接机构动力学建模;(3)基于动力学模型的控制方法. 本文最后提出了模块化可重构机器人动力学研究中若干值得关注的问题.     

Deflection characteristics of some special configurations of snake-type robots

The redundant robots analyzed here have large numbers of degrees of freedom. Such robots are analogous to snake or tentacles and are useful for operation in highly constrained environments and novel forms of locomotion — here it has been defined as critical manipulation. In this paper the end-point deflection of hyper-redundant robots have been studied by parameterization of the flexible links of the robot manipulator. A number of planar configurations of the redundant manipulator were taken into consideration for the present study and the configuration which gives minimum end-point deflection has been recommended for the critical manipulation. This work is significant for some of the research activities recently going on in NASA's Kennedy Space Center towards the application of hyper-redundant robots for manipulation inside the space Shuttle Cargo Bay.     

动态重构硬件加速中的性能开销建模

近年来,随着可重构计算方法和可重构硬件特性的不断演进,基于FPGA动态部分重构技术构建运行时可重构加速器已经成为解决传统加速器设计中硬件资源限制问题的重要途径.然而,区别于传统静态重构加速器,FPGA的动态重构开销是影响硬件加速整体性能的重要因素,而目前尚缺少能够在可重构硬件设计的早期阶段进行动态重构开销精确估算的相关...     

Automated Construction System of Robot Locomotion and Operation Platform for Hazardous Environments— Basic System Design and Feasibility Study of Module Transferring and Connecting Motions

Unmanned robot operation is highly anticipated for use in hazardous environments such as a nuclear accident and mine accident sites. We propose an automated construction system for robot locomotion and operation platform in a severely disturbed environment. In such an environment, the sensors and actuators that can be used are restricted. The platform is intended to enable specialized working robots to have access to any cube‐diced operation point, and to build a rail both for the platform itself and for specialized working robots. The entire platform structure is modularized, which means that the structure comprises multiple modules. They are assembled and constructed through cooperation of a transfer robot and a constructor robot. This paper describes the development of prototypes and explains experiments conducted to verify our fundamental concept. In particular, the feasibility of module‐transfer and connection motions in three prioritized positions is verified using the developed prototypes. The system design and experiments reveal that the most important technique to realize the proposed system is how to use guide structures to reduce the effects of mechanical error and misalignment among robots.     

一种基于FPGA的可重构计算系统设计

介绍可重构计算的概念和基于SRAM工艺的FPGA器件的特点。设计了一种基于FPGA器件的可重构计算系统,着重讲述了该系统的在线重配置电路的总体结构,FIFO、FPGA配置逻辑模块、控制寄存器和控制逻辑等功能模块及系统的工作流程。最后探讨了可重构计算相关研究面临的问题和发展方向。     

磁场与视觉共融的多模态胶囊机器人人机交互控制

为了实现磁驱动胶囊内窥镜基于定点悬停调姿的全景观察,提出一种欠驱动双半球胶囊机器人,突破了悬停调姿与滚动行走双重工作模态转换关键技术．为了在肠道弯曲环境内实现滚动行走,提出与视觉相融合的空间万向旋转磁场人机交互控制策略．理论上,依据正交变换推得经纬坐标系下以磁场轴线的侧摆角与俯仰角为独立变量的三相电流形式空间万向旋转磁场叠加公式,完成控制变量降维与解耦,实现磁场轴线沿侧摆或俯仰方向的单独调整;实践上,通过磁矩随动效应带动双半球形胶囊机器人摄像头分别实现侧摆与俯仰2个方向的独立扫描,使机器人轴线对准各段肠道弯曲方向,沿弯曲方向施加滚动磁矩实现胶囊机器人滚动转弯．最后,采用离体猪大肠模拟环境验证人机交互性能．试验表明,通过结合弯曲肠道图像与磁场方位的人机交互控制,既能实现双半球形胶囊机器人在被动模态下的姿态任意调整与全景观察,也能实现在主动模态下沿弯曲环境的滚动行走．     

CONRO: Towards Deployable Robots with Inter-Robots Metamorphic Capabilities

Metamorphic robots are modular robots that can reconfigure their shape. Such capability is desirable in tasks such as earthquake search and rescue and battlefield surveillance and scouting, where robots must go through unexpected situations and obstacles and perform tasks that are difficult for fixed-shape robots. The capabilities of the robots are determined by the design specification of their modules. In this paper, we present the design specification of a CONRO module, a small, self-sufficient and relatively homogeneous module that can be connected to other modules to form complex robots. These robots have not only the capability of changing their shape (intra-robot metamorphing) but also can split into smaller robots or merge with other robots to create a single larger robot (inter-robot metamorphing), i.e., CONRO robots can alter their shape and their size. Thus, heterogeneous robot teams can be built with homogeneous components. Furthermore, the CONRO robots can separate the reconfiguration stage from the locomotion stage, allowing the selection of configuration-dependent gaits. The locomotion and automatic inter-module docking capabilities of such robots were tested using tethered prototypes that can be reconfigured manually. We conclude the paper discussing the future work needed to fully realize the construction of these robots.     

Rapid design and reconfiguration of Petri net models for reconfigurable manufacturing cells with improved net rewriting systems and activity diagrams

To respond rapidly to the highly volatile market, the emerging reconfigurable manufacturing systems (RMS) have brought forward two challenging issues, namely, how to build rapid a formal model of an initial manufacturing configuration and how to yield the goal model from the existing one along with manufacturing configuration changes (reconfiguration). As for the issues, we present in this paper a method for rapid design of Petri net (PN) formalized models of RMS, intended for supervisory control and logic control of RMS, as well as a method for automated reconfiguration of the models. Firstly, we present an improved net rewriting system (INRS) for dynamically operating net transformation, unlike its predecessor-net rewriting system, where the initial behavioral properties of the underlying PN rewritten can be preserved during the transformation. Subsequently, the paper proposes the three-phase method for rapid design of initial full PN models of reconfigurable manufacturing cells (RMCs). In this method, activity diagrams of Unified Modeling Languages version 2 (UML 2) are used to describe manufacturing configurations, firstly; then the sub-activity diagrams are transformed into PN sub-models; finally, the PN sub-models are automated synthesized into a full model by the approach of INRS. Further, we present a model reconfiguration method for this class of PN models. The method compares changes in activity diagrams of the existing and goal manufacturing configurations and converts them into net rewriting rules of INRS. By applying the rules obtained, the existing PN model can reconfigure into a new one for the goal manufacturing configuration. No matter the design method or the reconfiguration method, the behavioral properties of the obtained PN models, e.g., liveness, boundedness, or reversibility, can be guaranteed and thereby the efforts of verification can be avoided. Finally, rapid design of a PN model of a reconfigurable manufacturing cell, as well as its automated reconfiguration, is illustrated with the help of an example. The result indicates the validity of the methods.     

A unified dynamic model for locomotion and manipulation of a snake-like robot based on differential geometry

A snake-like robot, whose body is a seried-wound articulated mechanism, can move in various environments. In addition, when one end is fixed on a base, the robot can manipulate objects. A method of dynamic modeling for locomotion and manipulation of the snake-like robot is developed in order to unify the dynamic equations of two states. The transformation from locomotion to manipulation is a mechanism reconfiguration, that is, the robot in locomotion has not a fixed base, but it in manipulation ha...     

水下模块化自重构机器人构形拓扑转换

定义了水下模块化自重构机器人构形拓扑转换基本概念 ,并分析总结出构形拓扑转换的基本规律 .然后采用遗传算法对构形拓扑转换进行优化 ,有效地降低构形拓扑转换操作过程中的连接和断开操作次数 ,提高自重构效率 .