先进机器人中的动力学与控制专刊序

围绕柔性机械臂动力学建模方法、空间机器人捕获动力学、多智能体控制、仿生跳跃机器人设计与分析等研究主题,本专刊介绍了先进机器人动力学与控制领域的一些最新研究成果.     

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.     

多飞行机器人吊运系统研究进展及挑战

多飞行机器人吊运系统是指由多个旋翼飞行机器人、吊绳及单个悬挂负载共同构成的具有空中操作能力的一类新型机电系统,具有灵活性强、地域可达性好、运输便捷、载荷能力强等显著优点.多飞行机器人吊运系统应用广泛,但是其建模与控制还存在诸多挑战.旋翼飞行机器人自身是一种复杂的欠驱动非线性系统,随着吊绳和负载的引入,系统的耦合性、欠驱动特性和非线性也会随之增加.为了全面对多飞行机器人吊运系统的研究进行综述,首先介绍了多飞行机器人吊运系统的常见构型,并对比分析了其优缺点;其次,从动力学建模、协调控制、实验三个方面介绍了多飞行机器人吊运系统的研究现状与挑战;最后,凝练了现存的关键科学问题,对其潜在的应用领域和未来的研究工作进行了探讨与展望.     

基于奇异摄动法的水下机器人优化PID控制

为了提高水下机器人位置控制的精确性,降低因系统耦合而造成的位置误差,提出了针对六自由度水下机器人的奇异摄动系统建模及控制方法.首先对水下机器人的姿态和位置进行动力学建模,将速度、角速度作为快变量,位置、姿态作为慢变量,从而把模型转换为奇异摄动系统模型,再对奇异摄动系统模型进行快慢分解,对快慢系统分别设计PID控制律,最...     

柔性两轮直立式自平衡仿人机器人的建模及控制

研究了柔性两轮直立式自平衡仿人机器人的动力学建模问题．运用拉格朗日方法和动力学原理建立了柔性两轮自平衡仿人机器人的动力学模型．使用弹簧模仿人的腰椎,并考虑了机器人的柔性腰椎弯曲;这是与以前机器人的不同之处．对得到的动力学模型进行了线性化处理,并建立其状态空间方程;由此建立的动力学模型结构简单,易于对机器人进行有效控制．仿真实验验证了系统的稳定性,对其实验结果进行的详细分析验证了系统建模和LQR控制器设计的合理性和有效性．     

水陆两栖仿生机器人构形、运动机理及建模控制综述

从水陆两栖机器人本体构形、推进动力学建模、多环境运动控制等方面对水陆两栖机器人近期的研究现状进行综述。首先,按照两栖机器人结构类型将两栖机器人分为腿式推进、轮腿/鳍复合式推进、蛇形推进、球形两栖机器人等;然后,介绍两栖机器人在水、陆环境中推进的动力学建模方法,以及目前常用于水陆两栖机器人的多环境运动控制策略。最后归纳得到两栖机器人的关键技术及未来发展方向,包括新型推进机构设计、系统建模、推进机理研究和多模态自主控制技术等。     

多机械臂协调控制研究综述

多机械臂系统的协调控制是当今机器人领域的研究热点.针对机器人基坐标系标定,协调系统动力学建模,控制器综合方法等问题,介绍近年来多机械臂系统在协调控制上研究工作的进展,主要从系统的动力学模型建立方式和协调运动的控制综合方式两个方面进行深入介绍.全面系统地介绍多机械臂系统协调控制问题的研究现状与发展方向,并指明未来工作的研究方向.     

七连杆双足机器人建模和控制系统仿真

研究双足机器人稳定性控制问题,步行机器人作为一种载运工具适应地况能力强,结构复杂,运动控制难.实现类人型机器人动态行走,针对行走的稳定性,必须对机器人进行动力学建模、步态设计和稳定姿态控制算法设计.研究了一种七连杆双足机器人的动力学建模和控制系统仿真方法.建立两足步行机器人腿的可参数化仿真模型,对七平面双足机器人的运动情况和控制输入输出进行仿真,得出试验结果.并对影响步行机器人稳定性能的参数进行分析,为后面机器人样机的研制提供理论及数据依据.     

基于Modelica的泵车臂架系统多领域耦合动力学建模与仿真

主要介绍一种基于 Modelica 语言的泵车臂架系统多领域耦合动力学仿真建模方法. 泵车臂架系统是典型的机械、液压、控制等多领域耦合系统,在其频繁的启动、制动过程中,变幅机构和液压元件均承受着强烈的冲击和振动. 传统的单一领域动力学建模方法很难全面反映泵车臂架系统的整体动力学性能,然而通过几种仿真工具进行联合仿真的方法亦难免存在建模效率、仿真速度等方面的问题. 针对以上不足,以某型泵车为研究对象,提供一种基于多领域统一建模语言 Modelica 的机械、液压及控制等多场耦合的泵车臂架系统动力学建模方法,并对其工作过程进行了动态仿真. 该模型具有模块化、层次化、规范化和参数化,以及仿真模型互操作性和重用性强的特点.     

平面双连杆受限柔性机器人臂的动力学建模*

对一类平面双连杆受限柔性机器人臂的动力学建模问题进行研究，利用Ｄ’Ａｌｅｍｂｅｒｔ－Ｌａｇｒａｎｇｅ原理得到了一组描述该机器人系统运动性态的动力学方程。与已有的动力学模型相比，本文所建立的运动方程和振动方程具有模型准确、结构简单等特点，且具有与传统无约束刚性机器人类似的模型形式，因而有可能直接或间接利用现有的关于刚性机器人运动控制等方面的成果来研究复杂的受限柔性机器人的控制问题。     

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．     

A generalized kinematic modeling method for modular robots

Modular robots can be defined as reconfigurable mechanical arms which can be automatically controlled using suitable motion control software. In this article, a generalized kinematic modeling method is presented for such modular robots. This method can be used to derive the individual kinematic models of all the mechanical elements that make up the inventory of modular units, independently of their geometry and sequence of assembly into a robot. A general procedure is also presented to derive a global kinematic model of any robot configured using these modular units. The kinematic modeling technique of the units is based on Denavit-Hartenberg (D-H) parameter notation. A provision is also presented for converting “non D-H” parameter transformations, obtained in assembling the kinematic chain, into D-H transformations. This D-H conversion feature allows the modeling technique to preserve its generality when a kinematic model is obtained for the specific robot configuration at hand. The conceptual design of modular robot units that is under development in the Computer Integrated Manufacturing Laboratory (CIML) is also presented to show the feasibility of a modular approach to robot design and to clarify some of the mathematical for mulations developed in the article.     

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     

Modular Reconfigurable Robots in Space Applications

Robots used for tasks in space have strict requirements. Modular reconfigurable robots have a variety of attributes that are well suited to these conditions, including: serving as many different tools at once (saving weight), packing into compressed forms (saving space) and having high levels of redundancy (increasing robustness). In addition, self-reconfigurable systems can self-repair and adapt to changing or unanticipated conditions. This paper will describe such a self-reconfigurable modular robot: PolyBot. PolyBot has significant potential in the space manipulation and surface mobility class of applications for space.     

Dynamic Analysis and Distributed Control of the Tetrobot Modular Reconfigurable Robotic System

Reconfigurable robotic systems can be adapted to different tasks or environments by reorganizing their mechanical configurations. Such systems have many redundant degrees of freedom in order to meet the combined demands of strength, rigidity, workspace kinematics, reconfigurability, and fault tolerance. In order to implement these new generations of robotic system, new approaches must be considered for design, analysis, and control. This paper presents an efficient distributed computational scheme which computes the kinematics, dynamics, redundancy resolution, and control inputs for real-time application to the control of the Tetrobot modular reconfigurable robots. The entire system is decomposed into subsystems based on a modular approach and Newton's equations of motion are derived and implemented using a recursive propagation algorithm. Two different dynamic resolution of redundancy schemes, the centralized Jacobian method and the distributed virtual force method, are proposed to optimize the actuating forces. Finally, distributed dynamic control algorithms provide an efficient modular implementation of the control architecture for a large family of configurations.     

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。     

动态企业建模(DEM)实施中的组件化方法

以一个先进的ERP建模工具DEM为例,探讨了在动态多变的企业环境下如何快速实施具柔性与扩展性的可配置的ERP系统。提出了组件化方法,对企业进行了四个层次的划分,在业务过程层引入业务组件的概念,以支持系统的柔性与可重构信息系统的开发。提出了采用DEM实施企业建模的步骤:企业层次化、组件层次化、业务组件化、模型层次化、组件集成化。国家863/CIMS应用示范工程SH-CIMSERP的实施证明了该方法的有效性。     

Rapid response manufacturing through a rapidly reconfigurable robotic workcell

This article describes the development of a component-based technology robot workcell that can be rapidly configured to perform a specific manufacturing task. The workcell is conceived with standard and inter-operable components including actuator modules, rigid link connectors and tools that can be assembled into robots with arbitrary geometry and degrees of freedom. The reconfigurable “plug-and-play” robot kinematic and dynamic modeling algorithms are developed. These algorithms are the basis for the control and simulation of reconfigurable robots. The concept of robot configuration optimization is introduced for the effective use of the rapidly reconfigurable robots. Control and communications of the workcell components are facilitated by a workcell-wide TCP/IP network and device-level CAN-bus networks. An object-oriented simulation and visualization software for the reconfigurable robot is developed based on Windows NT. Prototypes of the robot workcells configured to perform the light-machining task and the positioning task are constructed and demonstrated.     

基于SOA的动态服务集成与调度网格模型

针对在动态分布的网格环境中实现服务组件的动态选择和集成问题,提出基于SOA动态服务集成与调度系统DISS。引入组态和动态重构思想,给出DISS实现框架和方法,使网格应用的组态可以动态调整,实现服务组件的动态绑定,对该系统进行建模和原型实现,为建立面向服务架构的网格应用提供新的设计思想和实现方法。     

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.