可重构模块化机器人研究

可重构模块化机器人是机器人学的一个新的发展方向,其研究的核心和基础问题是可重构机器人的模块设计以及模块组合的运动规划。设计了一种新型可重构模块化机器人,该机器人具有独特的平面连接机构,实现了结构、驱动、运动和功能的模块化,能够根据需要重新构形,完成实时任务。分别介绍了模块单元的机械结构设计、连接机构以及基于CAN总线的控制系统结构。构建了基于OpenGL技术和VC++开发平台的机器人仿真实验系统,仿真机器人构形和运动,验证了模块设计的正确性和整体运动构形规划方法的有效性。     

同构阵列式自重构机器人的仿真与控制

针对同构阵列式模块化自重构机器人的特点,说明该机器人系统是一个分布式的多智能体系统,结合agent技术,对自重构模块的组成进行了分析,并提出一种能够准确描述该类机器人的拓扑结构、运动、位置及模块间连接关系的特征向量矩阵;对自重构模块的翻转、平移运动和元模块的构成及运动形式进行了描述,搭建了分布式多智能体的控制结构,结合模块的空间矢量进行路径规划,利用Java3D技术建立了可视化的模块化自重构机器人仿真环境,在此平台上对模块的运动进行了仿真,验证了该控制算法和仿真平台的有效性。     

一种自重构机器人手抓取构形的拓扑转换

自重构机器人手是由一些模块构成的复杂的模块化自重构机器人系统。本文提出了一种能够准确描述了这类机器人手抓取构形拓扑结构的方法;分析了构形拓扑转换的规律和步骤,并结合模块的运动形式,描述了拓扑结构转换的操作过程,并运用智能算法对构形拓扑结构转换进行优化。经验证,拓扑转换的操作步骤减少了,自重构机器人手的构形转化效率提高了。     

独立操作型可重构机器人群体构形表达和重构优化

独立操作型可重构机器人的单个模块具备独立运动、操作和采样能力,顺应从结构环境中定点作业向非结构环境中自主作业的发展要求,能够更好地应用到环境复杂、危险性高的场合.现有的构形研究主要针对依赖运动型、独立运动型可重构机器人,解决独立操作型可重构机器人构形问题时具有局限性.针对可重构机器人重构目的,提出矢量构形,将构形研究内容扩展到拓扑结构、运动趋势方向和各模块的姿态方位及连接关系,提出模块状态向量和构形状态矩阵实现该类可重构机器人群体构形的表达,对应的变换运算和操作可以表达、触发模块行为运动和构形重构,提出以工作负荷为优化目标的构形组合重构优化方法、以姿态方位工作负荷和连接工作负荷的组合为优化目标的构形变换重构优化方法,通过重构优化获得模块在构形重构中状态对应变换关系,作为构形重构规划和控制的基础.     

基于网络的自重构机器人重构路径研究

文中针对自重构机器人的重构问题提出了一种基于网络的分析方法.自重构模块机器人"AMOEBA-I"的9种不同构形组成了一个构形网络.机器人的每种构形被看成带有权值的有向构形网络中的一个节点.一种构形向另一种构形的转换可描述为一条非负值的有向路径.将图论应用于构形变化的分析,根据构形的拓扑信息相应定义了重构路径、可重构矩阵和路径矩阵.在此基础上,将图论中的算法应用于重构路径的计数和最佳重构路径的选择.数值分析与仿真实验结果验证了该方法的可行性.同时,该方法还可以用于其他自重构机器人的构形控制与自重构规划.     

自重构机器人的自组织变形

本文深入研究了自重构机器人实现自组织变形的基本方法．首先根据自重构机器人 系统结构的基本特征提出一种描述模型，可以对各类模块化自重构机器人的拓扑结构进行统 一描述．然后提出一种建立在全离散的局部智能基础上的自重构机器人的自组织变形策略， 通过建立适当的模块运动规则和规则进化使机器人由局部自主运动产生全局系统自组织的结 果．     

基于功能构件分解的机器人模块化设计方法

模块化机器人系统不仅包括模块化的机械硬件,而且还包括模块化电气硬件、控制算法和软件。模块的合理划分与重构是机器人模块化设计的重要研究内容。本文按照功能特征兼顾机器人的结构特征进行模块划分,提出基于功能构件划分的分层结构,即系统层一模块化单元层一功能构件层;并以服务机器人为例说明模块划分原则,具有功能独立性的最小模块单元的功能构件的特征以及识别功能构件的核心逻辑,阐述基于图论的运动学图和矩阵进行模块化机器人拓扑构形表达方法,通过引入接口向量来构造装配关联矩阵详细描述模块间的装配关系,介绍基于旋量理论的模块化可重构机器人运动学自动建模方法。     

基于快速重构机制的混合式失效检测算法

宇航、军事等关键应用领域的计算机系统对失效检测的时效性、可靠性、扩展性有高度需求.基于树状结构与环状结构的失效检测算法扩展性强,但前者单点失效问题严重,而后者的诊断延时较大,且在环结构破坏时成倍增长.为此,提出一种基于快速重构机制的混合式失效检测模型及相应算法.将系统进程集合划分为若干子集,子集内部使用环拓扑进行失效检测,并引入快速重构机制,当进程发生失效、环拓扑结构破坏时,使用逆向请求方法进行快速重构;子集之间采用层次结构进行心跳信息和失效信息的传播.实验表明算法具有良好的时效性,能够降低环拓扑破坏对诊断延时的负面影响.     

一种模块化可重构机器人系统的研制

在教育和科研领域中,为使机器人兼有较好的重构能力与操作性能,研制了一种模块化可重构机器人系统MRRES.提出了一种机器人模块划分及重构的方法,构建出机器人模块库,研制出集成传动、控制及传感于一体的系列化关节模块.基于Open GL和VC++开发了具有建模、仿真和运动控制功能的应用软件MRR-SIM.给出了一个基于任务和模块库的机器人设计实例,进行了实验测试.实验结果表明,MRRES系统模块划分和设计合理,机器人在保证重构能力的同时具有较好的操作性能,可应用于教育和科研等领域.     

模块化工业机器人嵌入式控制系统的研究

针对模块化机器人控制系统的重构问题,提出了一种柔性的嵌入式控制系统体系结构.该控制系统各种软硬件功能模块被抽取成标准构件,硬件模块设计采用了双核处理器以便满足计算能力和小型化的需求,模块之间通过标准的现场总线接口进行通信.机器人控制软件采用了基于构件的组态结构,它由柔性嵌入式控制系统开发平台、机器人功能构件库和运动规划与控制算法构件库三部分组成,实时性和非实时性的软件模块都按标准接口进行封装.机器人轨迹插补运算采用双DDA算法,逆运动学求解利用相邻轨迹点的关节坐标绝对增量最小原则去除冗余解.该嵌入式控制系统在六关节工业机器人选行了应用,实验结果表明它能适应机器人机械结构和作业任务的变化,使系统开发周期大大缩短.     

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.     

可重构模块化机器人现状和发展

由于市场全球化的竞争,机器人的应用范围要求越来越广,而每种机器人的构形仅能 适应一定的有限范围,因此机器人的柔性不能满足市场变化的要求,解决这一问题的方法就 是开发可重构机器人系统．本文介绍了可重构机器人的发展状况,分析了可重构机器人的研 究内容和发展方向．     

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.     

Kinematic Design of Modular Reconfigurable In-Parallel Robots

This paper describes the kinematic design issues of a modular reconfigurable parallel robot. Two types of robot modules, the fixed-dimension joint modules and the variable dimension link modules that can be custom-designed rapidly, are used to facilitate the complex design effort. Module selection and robot configuration enumeration are discussed. The kinematic analysis of modular parallel robots is based on a local frame representation of the Product-Of-Exponentials (POE) formula. Forward displacement analysis algorithms and a workspace visualization scheme are presented for a class of three-legged modular parallel robots. Two three-legged reconfigurable parallel robot configurations are actually built according to the proposed design procedure.     

Collision-free motion planning of dual-arm reconfigurable robots

Dual-arm reconfigurable robot is a new type of robot. It can adapt to different tasks by changing its different end-effector modules which have standard connectors. Especially, in fast and flexible assembly, it is very important to research the collision-free planning of dual-arm reconfigurable robots. It is to find a continuous, collision-free path in an environment containing obstacles. A new approach to the real-time collision-free motion planning of dual-arm reconfigurable robots is used in the paper. This method is based on configuration space (C-Space). The method of configuration space and the concepts reachable manifold and contact manifold are successfully applied to the collision-free motion planning of dual-arm robot. The complexity of dual-arm robots’ collision-free planning will reduce to a search in a dispersed C-Space. With this algorithm, a real-time optimum path is found. And when the start point and the end point of the dual-arm robot are specified, the algorithm will successfully get the collision-free path real time. A verification of this algorithm is made in the dual-arm horizontal articulated robot SCARATES, and the simulation and experiment ascertain that the algorithm is feasible and effective.     

Programming for modular reconfigurable robots

Composed of multiple modular robotic units, self-reconfigurable modular robots are metamorphic systems that can autonomously rearrange the modules and form different configurations depending on dynamic environments and tasks. The goal of self-reconfiguration is to determine how to change connectivity of modules to transform the robot from the current configuration to the goal configuration subject to restrictions of physical implementation. The existing reconfiguration algorithms use different methods, such as divide-and-conquer, graph matching, and the like, to reduce the reconfiguration cost. However, an optimal solution with a minimal number of reconfiguration steps has not been found yet. The optimal reconfiguration planning problem consists in finding the least number of reconfiguration steps transforming the robot from one configuration to another. This is an NP-complete problem. In this paper, we describe an approach to solve this problem. The approach is based on constructing logical models of the problem under study.     

A Reconfigurable Robot With Lockable Cylindrical Joints

This paper presents a new conceptual design for reconfigurable robots. Unlike conventional reconfigurable robots, our design does not achieve reconfigurability by utilizing modular joints. Rather, the robot is equipped with passive joints, i.e., joints without actuator or sensor, which permit changing the Denavit–Hartenberg (DH) parameters such as the link length and twist angle. The passive joints will become controllable when the robot forms a closed kinematic chain. Also, each passive joint is equipped with a built-in brake mechanism that is normally locked, but the lock can be released whenever the parameters are to be changed. Such a versatile and agile robot is particularly suitable for space application for its simple, compact, and light design. The kinematics and recalibration of this kind of reconfigurable robot are thoroughly analyzed. A stable reconfiguration-control algorithm is devised to take the robot from one configuration to another by directly regulating the passive joints to the associated, desired DH parameters. Conditions for the observability and the controllability of the passive joints are also derived in detail.      

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     

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.     

Configuration representation and reconfiguration optimization for the reconfigurable robots with independent manipulation

Single module of the reconfigurable robots with independent manipulation can perform the actions of locomotion and manipulation. In conformity with the request for achieving autonomous operation in the unstructurized environment instead of fixed operation in the structurized environment, these robots are applied in the complicated and dangerous environment. The existing researches on the configuration theory focus on the reconfigurable robots with limited locomotion and the ones with independent locomotion, not being applicable to the reconfigurable robots with independent manipulation. The vector configuration is put forward, the research content of which contains the topology and locomotion direction of configuration, the posture and orientation and connection relation between modules. Module state vector and configuration state matrix are proposed for representation methodology for the swarm configuration of these reconfigurable robots, which supports transformation operation to represent and trigger behavior motion of the module and reconfiguration between configurations. Optimization algorithm of assembly reconfiguration applying workload as the optimization target is presented, as well as optimization algorithm of transformation reconfiguration applying the integration of posture orientation workload and connection workload. The result of optimization is the relation of state transformation between the initial configuration and the object one as the basic of reconfiguration plan and control. Supported by the National High-Tech Research and Development Program of China (Grant No. 2006AA04Z254) and the Scientific Research Fund for Doctor of Liaoning Provice (Grant No. 20071007)