基于主动网络的MANET路由研究*

通过对主动网络和移动Ad hoc网络特点的分析,提出了将主动网络与移动Ad hoc网络相结合的思想,分析了这种结合的可行性和有效性.根据用户传输数据的大小和对路由可靠性的要求,提出了两种基于主动网络的移动Ad hoc网络的路由查找方法.仿真结果表明了采用主动网络技术后的移动Ad hoc网络能够方便地满足不同的路由要求.     

Ad hoc网络及其安全性分析

Ad hoc网络是一种特殊的多跳移动无线网络,具有广泛的应用场合。文中介绍了Ad hoc网络的产生、定义、特点和应用,然后在探讨Ad hoc网络的安全需求的基础上,分析了移动Ad hoc网络易于遭受的攻击,并集中讨论了移动Ad hoc网络的路由安全、密钥管理等关键问题。提出了按移动Ad hoc网络的安全需求进行分级,然后分别实现的解决策略。     

Ad hoc网络及其安全性分析

Ad hoc网络是一种特殊的多跳移动无线网络，具有广泛的应用场合。文中介绍了Ad hoc网络的产生、定义、特点和应用，然后在探讨Ad hoc网络的安全需求的基础上，分析了移动Ad hoc网络易于遭受的攻击，并集中讨论了移动Ad hoc网络的路由安全、密钥管理等关键问题。提出了按移动Ad hoc网络的安全需求进行分级，然后分别实现的解决策略。     

移动Ad hoc网络组播路由协议研究

移动Ad hoc网络是由一组移动终端组成的无线多跳自治系统,在军事、灾难救助、临时会议等场合应用.多数应用需要提供面向组的服务,因此Ad hoc网络环境下的组播路由协议研究成为当前的一个热点,首先分析比较了多种典型的Ad hoc组播路由协议,最后对Ad hoc组播路由协议做了总结和展望.     

移动Ad hoc网络路由安全性研究

路由协议安全性问题是移动Ad hoc网络研究重要课题。对移动Ad hoc网络路由协议中存在的安全问题和典型解决方案做了综述和分析。根据所适用的算法,将安全路由协议及其改进策略进行了分类。对路由安全性研究有较好的借鉴意义。     

一种节能的Ad hoc网络路由协议

针对Ad hoc网络中移动节点能量有限的问题,综合考虑节点剩余能量和节点能量消耗速率两方因素,提出一种基于节点生存时间的路由算法MRL（Maximum Routing Life）。通过估算节点使用寿命,选择生存时间最长的路由,均衡移动网络中各节点的能量。引入NS能量模型,与Ad hoc网络中典型路由协议进行比较;仿真结果表明,与传统路由协议相比,新的路由协议有效地提高了Ad hoc网络性能。     

基于RTI的统计分析方法检测与防御虫洞攻击

移动Ad hoc网是一种新型的无线移动网络,具有无中心、自组织、拓扑结构动态变化以及开放式通信等特性,使得Ad hoc网络易遭受攻击.虫洞攻击是针对Ad hoc路由协议的攻击,对Ad hoc网络造成的威胁最大.提出一种基于RTT(往返时间)的统计分析检测方法,在路由发现过程中,目的节点在返回路由应答(RREP)之前统计...     

一种基于Agent的Ad hoc网络路由算法

Ad hoc网络因其具有分布式、无中心、自组织、节点可以移动等特点,在军事通信、灾后紧急救援、传感器网络、局域网、车辆通信等方面有着广阔的应用前景,成为研究领域的一个热点.但同时由于Ad hoc网络拓扑结构的动态变化,使得作为Ad hDc网络关键技术之一的路由算法的实现较为困难.提出了一种基于Agent的Ad hoc网络路由算法,设计并实现了4种Agent.该算法通过在Ad hoc网络中加入一定数量的移动Agent来进行路由探寻,一方面降低了网络负载,另一方面降低了网络发送数据的时延.其实质是在现有的表驱动路由算法和按需驱动路由算法之间寻求一个折中.     

基于MAODV的移动多播路由协议的改进与仿真

移动Ad hoc网络是指由一组带有无线收发装置的移动节点组成的一个多跳的、不需要固定中心接入点或者基站支持的自治系统。对移动Ad hoc网络多播路由中的MAODV协议进行理论分析,提出了一种使用转接机制改进MAODV协议的方法,该改进协议使用新的NACK抑制机制来防止NACK风暴,减少了移动Ad hoc网络中大量的路由重构和数据分组的重传。采用OPNET软件进行仿真,仿真结果证明了该改进协议在Ad hoc网络中的可行性和有效性。     

Ad hoc网络稳定的蚁群多路由算法

移动Ad hoc网络又称MANET,具有多跳路由和拓扑动态变化的特点,是一种特殊的无线移动通信网络。本文提出了一种基于稳定拓扑和蚁群优化的Ad hoc网络多路由算法SAMR。     

Ad hoc网络路由技术分析

Adhoc网络是一种没有有线基础设施支持的移动网络,网络中的节点均由移动主机构成。本文主要针对其关键技术,网络拓扑以及路由协议和IP配置等几个方面对Adhoc的网络路由进行分析。     

机械人移动轨迹的智能PID控制

过程控制系统广泛的采用PID控制,它的系统直接关系到生产过程的平稳和产品的最终质量,因而其优化设计十分重要。常规PID控制得到了广泛的应用,但是不难满足高精度要求。智能PID控制吸取了智能控制和常规PID控制的优点,能够满足很多场合的高精度的要求。用于机械人移动控制取得了很好的效果。采用神经网络,可实现对机器人动力学方程中未知部分的精确逼近,从而实现无需建模的控制。     

面向对象的有限空间内人群流动CA模型研究

为了模拟在有限空间中大量人员的流动分布，基于面向对象技术，在已有交通流模型和行人流模型的基础上，建立了一个在有限空间内高密度人群流动的元胞自动机模型。采用面向对象思想的建模方法，使得模型具有很好的适用性、扩展性和复用性。并根据出现高密度人群的一般情况和控制对象的需求，提出“元胞控制块”的概念，使整个模型架构具有很强的应用转化能力。计算机模拟验证的结果良好，充分显示了元胞自动机模型对复杂人群流动的模拟能力。     

基于插中的人体步行运动控制研究*

以人体步行运动为研究对象,通过构造人体几何和运动模型,引入辅助关节角将插中原理与已有运动控制的方法结合起来,提出一种新的方法自动灵活地控制每个周期下的人体步行的姿态.最后通过仿真证实了该方法的可行性.     

A multi-functional mobility assist device for sit-to-stand motion

This paper presents a multi-functional Sit-to-Stand (STS) assistive device¹, which seeks to improve the mobility of individuals with lower extremity weaknesses. While originally designed for a person suffering from post-polio syndrome who could not rise from a seated position unassisted, the device found its utility among overweight and elderly persons and physical therapists. There is a growing population aged 65 and up for whom this essential activity of daily life can be a painful task. Lack of availability of fully-assistive Sit-to-Stand devices, which provide the STS motion and also aid in ambulation presents an unmet need for such individuals. In this paper, we present a novel 6-bar Sit-to-Stand (STS) linkage mechanism integrated into the device, which follows the motion trajectory of the hip joint and provides a comfortable orientation of the supporting bar during the motion. The device is positioned both as a functional assistive device meant for end-users constrained to stay at home due to their disability as well as an ambulation therapy aid to assist physical therapists and care providers to help them lift patients. The device, during the development stage, was tested at several assisted living facilities and nursing homes and is currently being used nationwide.     

机器人寻迹行走控制系统设计与实现

机器人寻迹技术广泛应用于工业生产中,该文提出一种基于AVR单片机为核心的寻迹机器人控制系统设计方案。系统采用光电检测寻迹,直流电机驱动的机器人控制技术,给出系统硬件及软件算法。最后通过实验证明设计出的寻迹机器人系统稳定,可靠性高,扩展性强。     

Estimation and volitional feedback control of active work rate during robot-assisted gait

Body weight supported robotic-assisted devices are normally used in gait rehabilitation of neurologically impaired persons but also have potential for application in cardiopulmonary rehabilitation. In this paper, a method of estimating and controlling the rate of active work done during supported stepping is proposed and experimentally validated through ambulation of three subjects with a spinal cord injury. The estimation and feedback scheme enabled work rates to be produced in close agreement to reference values. The efficacy of the proposed control scheme will facilitate the use of the technology in cardiopulmonary training and testing protocols.     

Myriapod-like ambulation of a segmented microrobot

Segmented myriapod-like bodies may offer performance benefits over more common fixed body morphologies for ambulation. Here, the design of a segmented ambulatory microrobot with a flexible backbone is presented. A dynamic model describing the motion of the microrobot is used to determine body parameters. A three-segment microrobot was fabricated using the Smart Composite Microstructures process and piezoelectric bimorph actuators, and forward locomotion on a flat surface was demonstrated. The footprint of the 750 mg microrobot is 3.5 by 3.5 cm, and it has potential advantages over rigid body hexapedal microrobots in climbing, versatility, and stability.     

Functional electrical stimulation

Percutaneous intramuscular electrodes and a portable multichannel system were used to restore the function of paralyzed upper and lower extremities in spinal cord injuries and hemiplegic patients. The hybrid functional electrical stimulation (FEC) using percutaneous intramuscular electrodes provides practical ambulation for paraplegics. FES was more effective than the flexor hinge splint in increasing the grasping power (GP) of tetraplegic patients, and a stronger and stable GP which was not affected by wrist position make FES practical for improving the activities of daily living. A tilt sensor, which was put on the thigh, could be used to measure a gait cycle. This study suggests that putting a tilt sensor on a hemiplegic patient's thigh improves the FES procedure and may help to restore gait in these patients. We conclude that percutaneous intramuscular FES is useful for spinal cord injuries and hemiplegic patients.     

Multi-Segment Foot for Human Modelling and Simulation

Realistic modelling of a human-like character is one of the main topics in computer graphics to simulate human motion physically and also look realistically. Of the body parts, a human foot interacts with the ground, and plays an essential role in weight transmission, balancing posture and assisting ambulation. However, in the previous researches, the foot model was often simplified into one or two rigid bodies connected by a revolute joint. We propose a new foot model consisting of multiple segments to reproduce human foot shape and its functionality accurately. Based on the new model, we develop a foot pose controller that can reproduce foot postures that are generally not obtained in motion capture data. We demonstrate the validity of our foot model and the effectiveness of our foot controller with a variety of foot motions in a physics-based simulation.