Layout modeling and construction procedure for the arrangement of exhibition spaces in a fair

This paper tackles a subset of layout problems that is not a subject of the scientific research to date: the arrangement of the exhibition spaces in a fair. A fair is a large‐scale exhibition for goods and services; for example a trade fair or a regional fair. The layout problem of fairs consists in finding an acceptable layout for both the exhibitors, the visitors, and the organizer of the fair. A model for representing the layout of fairs is presented: the adjacency model. Based on the adjacency model, a construction procedure is developed that leads to the generation of alternative layout solutions. Numerical results for the layout of a real fair are reported.     

自由飞行空间机器人研究综述

本文对自由飞行空间机器人的研究进行了介绍．首先，论述了自由飞行空间机器人的 概念、用途和运动特性．其次，分别从基本理论、地面实验平台和空间实验系统三个方面阐 述了自由飞行空间机器人的研究现状．最后，给出了结论和展望．     

Accuracy of finite dimensional dynamic models of flexible manipulators for controller design

The dynamics of mechanical systems with distributed flexibility are described by infinite dimensional mathematical models, yet a real controller must be finite dimensional due to the limited bandwidth capabilities of the sensor-actuator system and real-time control computer hardware. Therefore, simplified finite dimensional dynamic models must be obtained for the purpose of controller design. This article addresses the issue of selecting the shape and number of mode functions in developing finite order models using a flexible robot arm as an example. The results of this work have consistently shown that the clamped-free mode shape predicts the closed-loop system dynamics under a feedback controller much more accurately than pinned-free mode shapes. However, as the hub inertia increases relative to the flexible beam inertia the difference between the clamped-free and pinned-free mode shape model predictions becomes smaller.     

Robots in space - a survey

The paper tries to outline the state of the art in space robotics. It discusses the technologies used in ROTEX, the first remotely controlled space robot which flew with the shuttle Columbia in April 1993, but it also gives a review of the major space robot projects envisioned by different nations for the next decade. The mechatronics and dynamics aspects of space robots including free-flying systems are briefly discussed. Broader attention is given to the telerobotic and teleoperational control loop structures, including predictive delay-compensating graphics simulation. The paper finally tries to emphasize that by task-level programming (involving 'learning by showing' on a high level) future space robots will be powerful tools for scientists and ground operators which are not robot specialists. The tele-sensor programming concept of ROTEX was a first step in this direction. We plead for flying a variety of space robot systems in the near future in order to enhance experience with and confidence in these technologies as quickly as possible.     

Dynamics and Noncollocated Model‐Free Position Control for a Space Robot with Multi‐Link Flexible Manipulators

In this paper, both the dynamics and noncollocated model‐free position control (NMPC) for a space robot with multi‐link flexible manipulators are developed. Using assumed modes approach to describe the flexible deformation, the dynamic model of the flexible space robotic system is derived with Lagrangian method to represent the system dynamic behaviors. Based on Lyapunov's direct method, the robust model‐free position control with noncollocated feedback is designed for position regulation of the space robot and vibration suppression of the flexible manipulators. The closed‐loop stability of the space robotic system can be guaranteed and the guideline of choosing noncollocated feedback is analyzed. The proposed control is easily implementable for flexible space robot with both uncertain complicated dynamic model and unknown system parameters, and all the control signals can be measured by sensors directly or obtained by a backward difference algorithm. Numerical simulations on a two‐link flexible space robot are provided to demonstrate the effectiveness of the proposed control.     

散乱点云的三角划分算法研究

通过对当前的三角网格划分方法进行比较分析,提出了一种散乱点云的3D三角网格划分算法。该算法不需如同二维划分方法那样要对散乱点云对应的自由曲面分片投影,而是直接在3D空间,根据离散点集所对应的曲面形态变化,利用网格扩展、边界环分裂和边界环封闭,逐层收缩生成三角网格。该算法能方便地处理空间多种曲面的散乱点云数据,并且生成的三角网格形态优良,布局合理。     

Nonlinear feedback control of robot manipulator and compliant wrist

Many robotic applications require the direct contact of the end-effector with the environment. Passive compliance attached to the robot wrist, hand, or finger is desirable to produce smooth transitions between the free motion and contact, as well as to allow self-correction in order to accommodate geometric uncertainties in assembly and manufacturing. However, the use of passive compliance degenerates the positioning capability of the manipulator when the robot moves in free space. When the robot makes contact on workpiece, active adjustment of stiffness for various tasks in different directions is needed. We proposed to use passive compliance that is instrumented so that the system provides the necessary flexibility and also sensing to actively control the contact forces or to compensate the positioning error during motion and contact. In this article, the dynamic control of the manipulator with a compliant wrist is addressed. The measured deformation information of the instrumented compliant wrist is utilized in the feedback loop to increase the stiffness of the overall system in position control and to decrease the stiffness in force control. The dynamics model for both unconstrained and constrained cases is established. Applying nonlinear feedback control techniques, the dynamics of the manipulator-wrist system is linearized and decoupled, which allows the controller design to be carried out by using the linear system theory. Editor: J.M. Skowronski     

Topology and detail geometry optimization for beam structures using homotopy modeling

This paper describes a novel design concept and an algorithm for topology and detail geometry design of a beam structure. Topology, layout, cross-sectional shape and size of each element are treated as a design variable. Homotopy theory is used to classify a topological type of a beam structure. In the design concept, not topology itself of a structure but a detail geometry design space defined by topology is transformed. By introducing the novel concept of an algebraic topology expression and the topology metamorphosis algorithm, active topology transformation becomes possible. A numerical example of topology, layout and cross-sectional optimization of reinforcement for a beam structure is illustrated.     

机器人力控制仿真试验与研究

为了解决机器人在特定接触环境操作时对可以产生任意作用力柔性的高要求和机器人在自由空间操作时对位置伺服刚度及机械结构刚度的高要求之间的矛盾.对机器人力控制问题进行了研究,利用机械动力学仿真软件ADAMS/VIEW建立关节机器人的虚拟样机模型,通过其输入输出接口实现与MATLAB的通信,基于SIMULINK建立关节机器人力控制系统模型,将联合仿真概念引入到机器人力控制领域,最后进行仿真试验,对控制算法进行仿真验证,以提高控制精度和控制质量,通过对仿真结果的分析和处理证明此方法的合理性和有效性,为机器人力控制提供了一套有效的分析方法.     

财务人员考试及评分系统的设计与实现

文章介绍了财务人员考试及评分系统的主要功能,对各功能模块中所涉及到的一些关键算法的设计给出了实现方法,尤其对极具通用性的扣分标准的实现给出了较为详细的算法。     

Group‐in‐a‐Box Meta‐Layouts for Topological Clusters and Attribute‐Based Groups: Space‐Efficient Visualizations of Network Communities and Their Ties

An important part of network analysis is understanding community structures like topological clusters and attribute‐based groups. Standard approaches for showing communities using colour, shape, rectangular bounding boxes, convex hulls or force‐directed layout algorithms remain valuable, however our Group‐in‐a‐Box meta‐layouts add a fresh strategy for presenting community membership, internal structure and inter‐cluster relationships. This paper extends the basic Group‐in‐a‐Box meta‐layout, which uses a Treemap substrate of rectangular regions whose size is proportional to community size. When there are numerous inter‐community relationships, the proposed extensions help users view them more clearly: (1) the Croissant–Doughnut meta‐layout applies empirically determined rules for box arrangement to improve space utilization while still showing inter‐community relationships, and (2) the Force‐Directed layout arranges community boxes based on their aggregate ties at the cost of additional space. Our free and open source reference implementation in NodeXL includes heuristics to choose what we have found to be the preferable Group‐in‐a‐Box meta‐layout to show networks with varying numbers or sizes of communities. Case study examples, a pilot comparative user preference study (nine participants), and a readability measure‐based evaluation of 309 Twitter networks demonstrate the utility of the proposed meta‐layouts.     

等距线的B样条光顺逼近

本文用均匀Ｂ样条曲线光顺逼近Ｂ样条曲线的等距线，并且通过曲率值的修正，调整等距线的形状。本文还使用了非线性优化技术。     

Analyses of biped walking posture by dynamical-evaluating index

In this paper, biped walking posture and design are evaluated through dynamic reconfiguration manipulability shape index (DRMSI). DRMSI is the concept derived from dynamic manipulability and reconfiguration manipulability with remaining redundancy. DRMSI represents the ability of dynamical system of manipulators possessing shape changing acceleration in task space by normalized torque inputs, while the hand motion is assigned as the primary task. Besides, we use visual lifting approach to stabilize the walking and stop falling down. In this research, the primary task is to make the position of the head direct to the desired one as much as possible. And realizing the biped walking is the second task. This research indicates that proposed dynamical-evaluating index is effective in evaluating the biped walking motion and biped humanoid robot has the adjustable configuration to walk with higher flexibility. Flexibility represents the dynamical shape changeability of humanoid robot based on redundancy of the humanoid robot with the premise of the primary task given to keeping the head position high.     

网上博览会虚拟要素实时生成技术

在互联网上建立虚拟展馆,能够突破时间和空间的限制,满足世界各地更多的参观人群对参观展会的需求.针对虚拟展馆和现实展馆息息相关的问题,提出了"虚实融合"、"场网联动"的网上博览会设计与构建方法.重点研究了与现实相关联的虚拟展馆中关键要素包括人物和虚拟场景的实时生成技术,符合X3D标准,数据量小,易于网上发布,有效增强了网上博览会的生动性,同时将为现场参观人群提供有效的导览和服务信息.     

Tele-Presence in Populated Exhibitions Through Web-Operated Mobile Robots

This paper presents techniques that facilitate mobile robots to be deployed as interactive agents in populated environments such as museum exhibitions or trade shows. The mobile robots can be tele-operated over the Internet and, this way, provide remote access to distant users. Throughout this paper we describe several key techniques that have been developed in this context. To support safe and reliable robot navigation, techniques for environment mapping, robot localization, obstacle detection and people-tracking have been developed. To support the interaction of both web and on-site visitors with the robot and its environment, appropriate software and hardware interfaces have been employed. By using advanced navigation capabilities and appropriate authoring tools, the time required for installing a robotic tour-guide in a museum or a trade fair has been drastically reduced. The developed robotic systems have been thoroughly tested and validated in the real-world conditions offered in the premises of various sites. Such demonstrations ascertain the functionality of the employed techniques, establish the reliability of the complete systems, and provide useful evidence regarding the acceptance of tele-operated robotic tour-guides by the broader public.     

Spatial planning for musical output

This article describes an expert system called ENGRAVE that produces musical notation. This task is a resource allocation problem involving the layout of musical objects in space. to do this, we use a spatial planning technique called constraint guidance to plan the layout of the music. an example is given to illustrate the technique. an additional example is given in another domain to show that constraint guidance has general applicability for spatial planning problems.     

A dynamic safety system based on sensor fusion

Machines in industry, including industrial robots, have in many cases dramatically reduced the man-made work and improved the work environment. New machines introduce, however, new risk factors. Traditionally machines are safeguarded by means that more or less rigidly separates the machines from the personnel. This works well in many traditional areas, i.e., where industrial robots are involved. There is however a risk that the safety system limits the valuable flexibility of the robot, which can be considered as a quality that tends to become even more valuable in the progress of programming possibilities and sensor technology. This article shows an example how a safety system can be designed to achieve increased flexibility in co-operation between human and production safety strategy. The proposed safety system is totally based on sensor information that monitors the working area, calculate the safety level and improve the system dynamically, e.g., reduce the robot capability in conjunction to the system safety level. The safety system gain information from the sensors and calculates a risk level which controls the robot speed, i.e., the speed is reduced to achieve a sufficiently low risk level. The sensor data is combined with fuzzy-based sensor fusion and fuzzy rules. The safety system is based on sensor information, hence it automatically adjusts to changes in the guarded area as long as the functionality of the sensors is maintained. Finally, we present a system implementation in an industrial robot application.     

Motion coordination and reactive control of autonomous multi-manipulator systems

The emerging field of service robots demands new systems with increased flexibility. The flexibility of a robot system can be increased in many different ways. Mobile manipulation—the coordinated use of manipulation capabilities and mobility—is an approach to increase robots flexibility with regard to their motion capabilities. Most mobile manipulators that are currently under development use a single arm on a mobile platform. The use of a two-arm manipulator system allows increased manipulation capabilities, especially when large, heavy, or non-rigid objects must be manipulated. This article is concerned with motion control for mobile two-arm systems. These systems require new schemes for motion coordination and control. A coordination scheme called transparent coordination is presented that allows for an arbitrary number of manipulators on a mobile platform. Furthermore, a reactive control scheme is proposed to enable the platform to support sensor-guided manipulator motion. Finally, this article introduces a collision avoidance scheme for mobile two-arm robots. This scheme surveys the vehicle motion to avoid platform collisions and arm collisions caused by self-motion of the robot. © 1996 John Wiley & Sons, Inc.     

Uniform and self-stabilizing token rings allowing unfair daemon

A distributed system consists of a set of processes and a set of communication links, each connecting a pair of processes. A distributed system is said to be self-stabilizing if it converges to a correct system state no matter which system state it starts with. A self-stabilizing system is considered to be an ideal fault tolerant system, since it tolerates any kind and any finite number of transient failures. In this paper, we investigate uniform randomized self-stabilizing mutual exclusion systems on unidirectional rings. As far as deterministic systems are concerned, it is well-known that there is no such system when the number 6 of processes (i.e., ring size) is composite, even if a fair central-daemon (c-daemon) is assumed. A fair daemon guarantees that every process will be selected for activation infinitely many times. As for randomized systems, regardless of the ring size, we can design a self-stabilizing system even for a distributed-daemon (d-daemon). However, every system proposed so far assumes a daemon to be fair, and effectively replies on this assumption. This paper tackles the problem of designing a self-stabilizing system, without assuming the fairness of a daemon. As a result, we present a randomized self-stabilizing mutual exclusion system for any size n (including composite size) of a unidirectional ring. The number of process states of the system is 2(n-1)     

Planning and obstacle avoidance in mobile robotics

The paper focuses on the navigation subsystem of a mobile robot which operates in human environments to carry out different tasks, such as transporting waste in hospitals or escorting people in exhibitions. The paper describes a hybrid approach (Roaming Trails), which integrates a priori knowledge of the environment with local perceptions in order to carry out the assigned tasks efficiently and safely: that is, by guaranteeing that the robot can never be trapped in deadlocks even when operating within a partially unknown dynamic environment. The article includes a discussion about the properties of the approach, as well as experimental results recorded during real-world experiments.