STM32F107的停车引导系统设计

本文设计的停车诱导系统以STM32F107微控制器为核心处理器,由RFID读卡器组成检测电路,用来检测停车场的车辆通过情况;有源RFID的无线模块发送信号,由检测模块将检测信号上传至上位机,由上位机控制停车场地面的指示灯(用来指示是否有车辆通过)的开启与关闭.采用Modbus通信协议进行控制和监控,实现了与外界环境相结合的人为可控智能闭环系统.     

High‐precision formation control of nonlinear multi‐agent systems with switching topologies: A learning approach

Arbitrary high precision is considered one of the most desirable control objectives in the relative formation for many networked industrial applications, such as flying spacecrafts and mobile robots. The main purpose of this paper is to present design guidelines of applying the iterative schemes to develop distributed formation algorithms in order to achieve this control objective. If certain conditions are met, then the control input signals can be learned by the developed algorithms to accomplish the desired formations with arbitrary high precision. The systems under consideration are a class of multi‐agent systems under directed networks with switching topologies. The agents have discrete‐time affine nonlinear dynamics, but their state functions do not need to be identical. It is shown that the learning processes resulting from the relative output formation of multi‐agent systems can converge exponentially fast with the increase of the iteration number. In particular, this work induces a distributed algorithm that can simultaneously achieve the desired relative output formation between agents and regulate the movement of multi‐agent formations as desired along the time axis. The illustrative numerical simulations are finally performed to demonstrate the effectiveness and performance of the proposed distributed formation algorithms. Copyright © 2014 John Wiley & Sons, Ltd.     

Design of a compact dual‐band folded‐waveguide bandpass filter using multilayer waveguide resonators

A novel compact dual‐band bandpass filter based on multilayer folded‐waveguide (FWG) structure is presented in this article.In this design, slots are used to realize direct coupling between adjacent resonators and apertures are adopted to implement cross coupling between non‐adjacent resonators.A new technique of external quality factor of FWG resonator and coupling coefficients between different resonators are studied using full‐wave simulator. In order to demonstrate the proposed technique, a four‐pole dual‐band bandpass filter is designed, fabricated and measured using vector network analyzer. Measurement results which are well agreed with simulation results are presented. Moreover, four‐pole substrate integrated folded waveguide SIFW dual‐band bandpass filter, using two layers of slotted folded waveguide resonators, is demonstrated. The proposed filter has a compact size and it is excellent candidate for the application of wireless communication systems. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:780–788, 2015.     

Efficient identity-based signature over NTRU lattice

Identity-based signature has become an important technique for lightweight authentication as soon as it was proposed in 1984. Thereafter, identity-based signature schemes based on the integer factorization problem and discrete logarithm problem were proposed one after another. Nevertheless, the rapid development of quantum computers makes them insecure. Recently, many efforts have been made to construct identity-based signatures over lattice assumptions against attacks in the quantum era. However, their efficiency is not very satisfactory. In this study, an efficient identity-based signature scheme is presented over the number theory research unit (NTRU) lattice assumption. The new scheme is more efficient than other lattice- and identity-based signature schemes. The new scheme proves to be unforgeable against the adaptively chosen message attack in the random oracle model under the hardness of the γ-shortest vector problem on the NTRU lattice.     

基于状态指标的更新决策方法研究

针对设备在实际运行和执行任务时经常涉及到维修、更新报废等管理活动缺乏定量模型支撑的问题,提出了利用典型部件的预测寿命和非典型部件的历史寿命对设备系统级的健康状态进行综合评估的方法,建立了一种以状态指标为决策序列的动态规划更新决策方法;该方法能综合考虑维修费用和更新费用,确定最优更新决策,降低保障费用,有效地提高了设备的经济效益;最后经过案例分析证明了该方法的有效性,对于提高设备的保障能力和经济效益提供了理论支撑和方法指导.     

面向虚拟试验的可视化应用生成工具研究与实现

虚拟试验能够很好地辅助实物试验,缩短型号研制周期,降低研制费用;虚拟试验应用工程是开展虚拟试验的基础,基于GEF图形编辑器,研究并实现了一种面向虚拟试验可视化应用生成工具,具有可视化应用工程编辑、应用工程框架代码生成等功能;支持在可视化界面中定义VOM图元和APP图元之间的发布、订阅关系,最终生成应用工程框架,并通过应用实例验证了该可视化应用生成工具的实用性,较好地提高了虚拟试验应用工程的开发效率.     

Switched visual servo control of nonholonomic mobile robots with field-of-view constraints based on homography

This paper presents a novel scheme for visual servoing of a nonholonomic mobile robot equipped with a monocular camera in consideration of field-of-view (FOV) constraints. In order to loosen the FOV constraints, the system states are expressed by the homography between the current frame and the key frame so that the target is not necessarily to be always visible in the control process. A switched visual controller is designed to deal with the nonholonomic constraints. Moreover, an iteration strategy is used to eliminate errors caused by the parameter uncertainty. The stablity and robustness of the proposed scheme are guaranteed by theoretical analysis. Compared to conventional schemes, the proposed approach has the following advantages: 1) a better path in Cartesian space can be achieved owing to the loosening of FOV constraints; 2) the iteration strategy ensures the robustness to parameter uncertainty; 3) when used in landmark-based navigation, it needs much sparser and simpler landmarks than those localization-based approaches need. Simulation results demonstrate the effectiveness of the proposed method.     

基于信息化高等教育评价指标体系的探索

针对高等教育信息化评价指标体系不够全面和完善,缺乏统一等问题,结合我国高校教育信息化的特点与现状,借鉴国内外高校信息化发展过程中的成果,运用多学科理论构建高等教育信息化评价体系。     

基于VXWORKS平台的网管代理软件开发

首先概要介绍了实现网管代理用到的简单网络管理协议(SNMP)和协议运行的操作系统(VXWORKS)平台;进一步对简单网络管理协议原理、管理结构、管理模型、协议内部操作方式、对应协议管理信息库加以说明;介绍代理软件运行的操作系统的特点和基本结构,并在以上2方面基础上详细地介绍了在VXWORKS系统上用ENVOY(SNMP)协议包实现网管代理基本流程,包括了协议配置、管理信息库(MIB)文件的编辑、协议加载。