Reality-augmented virtual fluoroscopy for computer-assisted diaphyseal long bone fracture osteosynthesis: a novel technique and feasibility study results

In this paper, a novel technique to create a reality-augmented virtual fluoroscopy for computer-assisted diaphyseal long bone fracture osteosynthesis and feasibility study results are presented. With this novel technique, repositioning of bone fragments during closed fracture reduction and osteosynthesis can lead to image updates in the virtual imaging planes of all acquired images without any radiation. The technique is achieved with a two-stage method. After acquiring a few (normally two) calibrated fluoroscopic images and before fracture reduction, the first stage, data preparation, interactively identifies and segments the bone fragments from the background in each image. After that, the second stage, image updates, repositions the fragment projection on to each virtual imaging plane in real time during fracture reduction and osteosynthesis using an OpenGL-based texture warping. Combined with a photorealistic virtual implant model rendering technique, the present technique allows the control of a closed indirect fracture osteosynthesis in the real world through direct insight into the virtual world. The first clinical study results show the reduction in the X-ray radiation to the patient as well as to the surgical team, and the improved operative precision, guaranteeing more safety for the patient. Furthermore, based on the experiences gained from this clinical study, two technical enhancements are proposed. One focuses on eliminating the user interactions with automated identifications and segmentations of bone fragments. The other focuses on providing non-photorealistic implant visualization. Further experiments are performed to validate the effectiveness of the proposed enhancements.     

A new certainty grid based mapping and navigation system for an autonomous mobile robot

A complete Bayesian derivation for a sensor data updating formula for certainty grids is given, and its validity confirmed in a simulation. In the real world this formula alone is less valid because of the specular reflection effect, which seriously detracts from the map quality. A simple and practical approach, which greatly enhances the map quality in spite of some loss of range information, is proposed to compensate for this. A new path planning method based on the enhanced map is implemented on a mobile robot, and every aspect of the new algorithm is investigated through a series of experiments. The results show the validity and usefulness of the proposed approaches, i.e. updating formulae, specular reflection correction and path planning methods.     

基于CAN网络小型直升机自动驾驶仪硬件及导航系统设计

本文介绍一种基于CAN网络的无人直升机自动驾驶仪的硬件系统结构与姿态导航原理。此系统采用GPS+INS组合导航系统,通过非线性卡尔曼滤波[1]计算飞机姿态与导航信息。     

基于仿真的生产系统规划技术研究

现代生产系统是复杂的离散制造系统,传统生产线的设计过多地依靠经验和手工演算,缺少科学性,很难达到预期结果.其中生产线的设计与生产线设备的利用率、产品的生产时间和生产线的效率等密切相关.采用先进的生产线规划与仿真技术,可以对生产系统的性能进行评价,在生产规划的早期对其系统进行优化与调整,以便得到较高的生产率.以某发动机缸盖的生产线的规划为对象,采用面向对象的离散系统仿真软件eM-Plant软件构建生产线仿真模型并进行了生产线生产能力、设备的利用率和生产效率的分析,为生产线的优化提供了技术依据.在此基础上采用生产线规划软件FactoryCAD构建了发动机缸盖生产线的3D数字模型,为发动机缸盖生产线的设计提供了技术依据.     

新型并联运动振动筛的筛分效率及其试验研究

并联运动振动筛是一种全新的三维运动振动筛,其筛面具有良好的理想运动轨迹,适于物料筛分。文中从影响筛分效率的因素入手,就曲柄转向、曲柄转速(工作频率)、投料方式、主机构杆长、安装倾角、振幅等几个方面进行试验方案设计并论证,揭示了并联运动振动筛特有的筛分特性和规律,试验结果证明,并联运动振动筛具有良好的透筛环境,筛分能力强,筛分效率高。     

基于MapX的导航程序的设计与开发

近年来,随着科学技术的迅猛发展,GPS和GIS在电子导航系统的应用日趋广泛并且研究也更加深入。该文介绍了建立在对象链接与嵌入技术基础上的地图控件MapX的数据结构、功能接口以及运行机制,并介绍了使用MapX开发电子导航系统中的地图模块的方法,文章最后设计了一种快速地图匹配算法。     

基于虚拟仪器的组合导航系统测试平台的设计

提出利用虚拟仪器技术开发测试平台的设计方法,详细介绍了某型组合导航系统测试平台的软硬件设计,重点分析了设计中难点问题及其解决方法.通过实际测试和用户使用,证实该测试平台具有系统性能稳定、可靠,操作方便,界面友好等特点.     

新型摩擦模型的参数辨识及补偿实验研究

针对影响运动控制性能的非线性摩控因素,对一种新型摩擦模型的参数辨识及其基于摩控模型的补偿进行了实验研究,详细地给出了摩控模型参数的辨识步骤及补偿算法,实验结果表明,此辨识方案及补偿算法可以应用于工业的高精度运动控制中。     

基于双DSP和FPGA的导航处理系统设计

机电技术的发展为惯性测量系统的大量应用奠定了基础。针对深海导航应用场合,为了提高深海惯性导航的精度和实时性,设计了基于双数字信号处理器（DSP）和可编程逻辑门阵列（FPGA）的捷联惯性导航计算机,成功构建了低成本、小型化的捷联惯性导航系统（SINS）。重点描述了双DSP和FPGA导航计算机的硬件设计思路。扼要介绍了系统软件的框架结构。与目前大多数的惯性导航系统相比,该系统体积小、重量轻、功耗低,适用于运算复杂的嵌入式惯性导航系统。实验室车载实验结果证明了上述设计的正确性和可行性。     

Concurrent process/inspection planning for a customized manufacturing system based on genetic algorithm

Producing products with multiple quality characteristics is always one of the concerns for an advanced manufacturing system. To assure product quality, finite manufacturing resources (i.e., process workstations and inspection stations) could be available and employed. The manufacturing resource allocation problem then occurs, therefore, process planning and inspection planning should be performed. Both of these are traditionally regarded as individual tasks and conducted separately. Actually, these two tasks are related. Greater performance of an advanced manufacturing system can be achieved if process planning and inspection planning can be performed concurrently to manage the limited manufacturing resources. Since the product variety in batch production or job-shop production will be increased for satisfying the changing requirements of various customers, the specified tolerance of each quality characteristic will vary from time to time. Except for finite manufacturing resource constraints, the manufacturing capability, inspection capability, and tolerance specified by customer requirement are also considered for a customized manufacturing system in this research. Then, the unit cost model is constructed to represent the overall performance of an advanced manufacturing system by considering both internal and external costs. Process planning and inspection planning can then be concurrently solved by practically reflecting the customer requirements. Since determining the optimal manufacturing resource allocation plan seems to be impractical as the problem size becomes quite large, in this research, genetic algorithm is successfully applied with the realistic unit cost embedded. The performance of genetic algorithm is measured in comparison with the enumeration method that generates the optimal solution. The result shows that a near-optimal manufacturing resource allocation plan can be determined efficiently for meeting the changing requirement of customers as the problem size becomes quite large.     

基于嵌入式系统的无线传感器网络的应用研究

无线传感器网络是集成了传感器、嵌入式系统、网络和无线通信四大技术而形成的一种全新的信息获取和处理技术,它是一种新型的无基础设施的无线网络,能够实时监测、感知和采集各种环境或监测对象的信息,并对其进行处理、传送到需要这些信息的用户.该文分析了嵌入式平台下无线传感器网络的组成原理及应用,同时给出了部分程序代码及仿真运行结果.     

中高轨星光折射导航光学系统设计及杂散光抑制

为了实现基于大视场星光折射敏感器的中高轨卫星全天时高精度星光折射导航,针对视场中亮地球引起的强杂散光抑制的技术难题,研究了内掩式星光折射敏感器亮地球杂散光的有效抑制方法。通过构建星光折射敏感器模型、搭建星光折射导航仿真观测环境以及原理计算得出了各级杂散光强度,并确定了相应的抑制方法。仿真结果表明,基于二次成像光学系统的内掩式星光折射敏感器可将杂散光抑制在导航系统的最大可接受杂散光抑制值范围内,即抑制后1.003Re(Re为地球半径)处杂散光亮度小于亮地球平均亮度的1.10×10~(-3)倍。最后,通过月球强背景下恒星探测外场试验验证了杂散光分析及抑制方法的可行性。研究成果为实现基于一个大视场星光折射敏感器的中高轨卫星全天时高精度星光折射导航技术奠定了基础。     

基于单片机的细胞动态张应力试验系统设计

针对目前国内外还没有一种可以给细胞样本试验提供动态张应力的试验系统的现状,作者研制了膜式变应力波细胞动态张应力试验系统,该系统采用了基于M68HC908J12单片机的DDC控制系统.本文论述了该试验系统的结构和工作原理,重点阐明了控制系统的工作原理,硬件结构,并给出了相应的软件流程图.经试验验证:该系统具有优良的控制精度和稳定性,经济可行.     

新型阻尼器的理论与试验研究

该文对新型阻尼器与活塞式阻尼器进行了理论对比分析,在此基础上,并对两种阻尼器进行了试验,理论和试验都表明,新型阻尼器比活塞式阻尼器更具有吸收比例阀控系统中的液压冲击和压力脉动的作用.     

Design and implementation of an Internet based effective controlling and monitoring system with wireless fieldbus communications technologies for process automation--an experimental study

The network requirements of control systems in industrial applications increase day by day. The Internet based control system and various fieldbus systems have been designed in order to meet these requirements. This paper describes an Internet based control system with wireless fieldbus communication designed for distributed processes. The system was implemented as an experimental setup in a laboratory. In industrial facilities, the process control layer and the distance connection of the distributed control devices in the lowest levels of the industrial production environment are provided with fieldbus networks. In this paper, the Internet based control system that will be able to meet the system requirements with a new-generation communication structure, which is called wired/wireless hybrid system, has been designed on field level and carried out to cover all sectors of distributed automation, from process control, to distributed input/output (I/O). The system has been accomplished by hardware structure with a programmable logic controller (PLC), a communication processor (CP) module, two industrial wireless modules and a distributed I/O module, Motor Protection Package (MPP) and software structure with WinCC flexible program used for the screen of Scada (Supervisory Control And Data Acquisition), SIMATIC MANAGER package program ("STEP7") used for the hardware and network configuration and also for downloading control program to PLC.     

基于遗传PNN网络的组合导航故障诊断研究

针对INS/GPS组合导航系统观测信息无冗余且观测信息可能存在故障的情形,提出一种基于状态x2检验与自适应概率神经网络( APNN)相结合的组合导航故障诊断方法.该方法通过监测组合导航系统状态分量,提取故障的特征值并利用APNN确定故障的类别,从而实现故障的定位与隔离.APNN采用高斯函数作为激励函数,通过遗传算法获得模式层矢量最佳数目及匹配的平滑因子参数集,使每个神经元传递函数具有不同的平滑参数,提高了网络的泛化能力以及诊断精度.数值仿真结果表明,该算法能够有效地识别出INS/GPS组合导航系统的故障,确保了系统的安全性和可靠性.     

一种新型惯导和气压组合导航系统的设计

本文通过对靶弹飞行特性的分析,设计了一种利用MOTOROLA MP×21 00压力传感器、单片机和XW-IMU5200惯导等器件为基础的组合高度导航系统.并通过对惯导误差、气压高度模型和大气数据等的分析,针对其飞行高度范围设计了一套实用的硬件系统.在软件上运用了卡尔曼滤波,并对其高度算法进行了改进.使得系统具有精度高、可靠性强、重量轻体积小、造价低廉等优点.     

基于VC＋＋的二维不规则零件排料系统开发

针对工业生产中经常出现的二维不规则零件的自动排料问题,提出一种新算法,验证该算法的可行性。并以VC＋＋作为平台,开发集图纸管理和自动排料为一体的自动排料系统,与传统排料系统相比,提高了材料的利用率和生产效率,具有很高的实用性和有效性。     

基于ARM和DSP的INS/GPS组合系统设计

为满足组合导航系统要求成本低、体积小、精度高、低功耗的特点,本文以SAMSUNG公司S3C2410型和TI公司TMS320C6713型芯片为核心器件设计了一种嵌入式导航计算机系统,此设计可提高系统的精度,更好地满足系统实时性的要求。