随着计算机技术发展和移动计算能力的提高,虚拟现实技术得到广泛应用.针对《计算机软件技术基础》理论课程和《计算机实践》实验课程要求,基于微软HoloLens全息智能眼镜和磁力驱动的力触觉交互模块,设计实现了视觉和力触觉融合的多模态虚拟现实实验系统,构建了符合课程教学要求的综合实验平台.基于这一综合实验平台,将计算机最新前沿技术引入课程教学,设计开发了综合性、创新性和开放性的实验项目,以此激发学生学习的积极性和主观能动性,巩固课程知识点,有效促进了学生计算机软件实践能力和创新能力的提高.

为提高嵌入式技术实验教学效果,基于桌面云构建了嵌入式技术创新实践硬件实验平台,开发了虚拟实验系统,研究了桌面云下虚实结合的实验教学模式,探索了基于桌面云的开放共享的互联网+实验教学模式,以及理论、实验和网络教学交叉融合的教学架构.研究成果可用于嵌入式技术课程教学,提高学生嵌入式应用系统设计、工程实践和科技创新能力,并可为互联网+教育背景下实验教学提供参考.

研究了一种基于深度置信网络的故障诊断方法,主要应用于针对航空发电机旋转整流器所进行的故障诊断中,对方法进行了仿真及实际实验验证.采集主励磁机励磁电流作为故障诊断所使用的有效信号,对所采集到的励磁电流信号进行快速傅里叶变换以获取其频域信息,将所得到的频域数据分为训练样本和测试样本输入至深度置信网络中进行故障分类,计算诊断正确率并做出分析.实验证明,所提出的方法具有良好的故障分类效果.

Correct incipient fault diagnosis is crucial to the health management of the analog circuits, though remaining challenging. This paper presents a novel fault diagnosis method to diagnose ordinary soft fault and incipient soft fault for linear analog circuit. Due to the presence of analog circuit noise stress and the tolerance of the components, the linear circuit responses are considered as a stochastic process; and the time responses are acquired by sampling the outputs of the circuits under test. In this study, the local mean decomposition (LMD) method is used to decompose the stochastic series into a set of functions, each of which is the product of an envelope signal and a frequency modulated signal. The noises are decomposed and extracted from the sampled signals, which are later reconstructed. In the next step, the fault signatures are extracted from the de-noised series by applying the improved wavelet transform. Then the de-noised series samples are randomly selected as the training sample group and testing sample group. Finally, the feasibility of the proposed method is tested by SVM classifier. The proposed incipient fault diagnosis procedure is performed and verified on a Sallen-Key band-pass filter circuit and a four-op-amp high-pass filter circuit, which reveals improved accuracy of the proposed approach.

针对“计算机实践”课程教学内容和实践性强的特点,阐明Kinect应用系统和课程内容(数据结构、操作系统、软件工程等)的紧密相关性.基于南京航空航天大学自动化学院近几年教学实践,提出将基于Kinect实验项目应用于“计算机实践”课程教学中.实践证明,引入Kinect应用系统实验项目,能有效培养和提高学生的实践能力、创新能力、自学能力和团队协作能力等,取得较好教学效果.

本科毕业设计是大学生的最后一个实践性教学环节,持续的时间较长,对于培养学生的系统性知识掌握和运用、知识创新和工程动手等各项能力都是一个十分重要机会.本文尝试将本科毕业设计与CDIO大纲的部分教育理念和元素加以契合,以其能够提高学生的工程实践能力和项目参与能力,为后续CDIO工程教育模式的进一步引入和运用提供有益的尝试.

Traditional fault tolerant methods for reconfigurable array can not control the process of reconfiguration automatically without the aid of a controller.In addition,these methods always have low resource utilization rate,and the reconfigurable control algorithm is complex.An online distributed self-fault tolerant method for three-dimensional reconfigurable array is proposed in this paper.The system is composed of the same electronic cells in a three-dimensional structure,and every cell can locate the fault and realize fault self-repair automatically.A re-routing mechanism based on breadth-first routing algorithm is used to find the redundant cell that costs least routing length in the three-dimensional cell array.The redundant cells are proportionally and evenly distributed in the three-dimensional array,which increases the flexibility of the control process of fault tolerant reconfiguration and reduces the reconfiguration time.A 4-bit parallel multiplier circuit was used to verify the fault tolerant capability and performance of this mechanism in reconfigurable array.Experiment results prove that the proposed method can realize distributed self-fault diagnosis and self-repair of three-dimensional reconfigurable array;and this method can not only allow multiple faults,but also minimize the fault tolerant reconfiguration time,and has a high redundant resource utilization rate.

The initial rotor position of brushless DC motor (BLDCM) is very important, not only for the anti-reverse rotation startup but also for the maximum starting torque. This paper analyzed the relation between the changing trends of the floating phase terminal voltages and the initial rotor position when voltage vectors were applied to the stator windings. A novel method was presented to estimate the initial rotor position based on the stator core saturation. In the proposed method, three voltage vectors were applied to the stator windings, and then, the changing trend of each floating phase terminal voltage was detected one by one. As a result, the 60 degree resolution could be achieved. This method can be implemented conveniently without current sensors, and is suited for sensorless BLDCM applications, in which low cost is the major consideration. The proposed method was validated by the results on the BLDCM experiment platform, which was controlled by the STM8S903K3 microprocessor. © 2012 Chin. Soc. for Elec. Eng.

Fault-tolerant system of Reconfigurable Hardware(RH) with centralized controller has the shortcomings of complex reconfiguration algorithm and long reconstruction time,and the system will be invalidation when the controller is in fail.To realize online distributed fault-tolerant in-chip,a new RH architecture of cell arrays was proposed,which has the ability to achieve in-chip self-repairing.The method of fault localization and self-repairing for interconnection circuit between electronic cells in RH are described in detail.The electronic cell circuit and a Fault-Tolerant Switch Block(FT-SB) in RH are designed.The fault-tolerant method of interconnection circuit includes two stages.Firstly,the MUXs in FT-SB and the connection lines between FT-SBs in the fault channels are detected,then the re-routing and line-shift methods in interconnection circuit are introduced to heal the fault MUXs and the broken lines respectively.The implementation and simulation experiment of a 4-bit serial-parallel multiplier are presented.The performance analysis of fault-tolerant time and hardware resources consumption show that the fault-tolerant performance of the interconnection circuits in new RH is improved greatly.

《数字系统设计》是面向电类专业学生开设的一门应用型课程。针对课程内容新颖,学生入门困难的问题,根据近几年课堂教学的实践,讨论阐述了该课程应该以电路设计为核心,在熟练掌握基本电路教学内容的基础上引入先进的数字系统设计方法的课程内容。实践环节中加强了设计分析步骤,实践过程以验证试验入门,以自主设计来强化,以科研应用介绍来拓展。

为了提高信号去噪的效果,提出了一种基于分数阶小波包变换(FRWPT)的信号去噪新方法.该方法根据输出信号信噪比的大小,用迭代法寻找分数阶小波包变换的最优分数阶p值,通过分数阶小波包变换将带噪信号映射到最优分数阶小波包时频域内,对变换后的信号进行窄带通滤波,最后通过分数阶小波包逆变换对信号进行重构,实现分数阶小波包时频域内的信号去噪.以带噪Bumps信号和语音信号为例的去噪实验结果表明,采用该方法去噪后的信号信噪比明显提高,在抑制噪声的同时可以有效保持细节信息.更多还原

根据VIIDL语言实践性较强的特点,提出教学方法:实验室教学法和专生、能力区别化教学法以及实验技能考核法,并针对几个VIIDL语言中的难点,给出条理清晰的解释.

The use of redundant rows for covering single cell faults,which possessed about 70% of the total faults,leaded to the waste of redundant resources. In order to improve utilization rate,an integrated ECC and redundancy repair scheme is proposed. In the proposed scheme,the redundancy repair and ECC techniques are used to correct multiple and single word faults. If the code rate (i.e.,the ratio of the length of information bits to code length) is lager than 1/2,ECC uses less area overhead to repair single word faults than redundant rows. The feasibility of the proposed scheme is justified on a 24×8-b SRAM. Experimental results demonstrate that both area overhead and maximum frequency are improved by the new approach.

A leakage listening detector with high performance and practicality is designed and developed based on the practical requirement from leakage detecting.Several functional parts such as JFET follower,high gain preamplifier,low pass filter and feedback circuit are integrated into the detector to both improve listening recognition and achieve a appreciable balance between listening recognition and noise suppression.Band pass filter(BPF) under the control of MCU can easily switch among the common-used frequency band.Simulation shows that the BPF meets the designed requirements.Test on the prototype detector indicates that the system operates excellently both in listening recognition and noise suppression,which completely satisfies the requirement specification.

A novel reconfigurable BOOTH multiplier was presented.The BOOTH encoder,partial product generator,compressor and final adder were designed with requirement of reconfiguration taken into full consideration,so the circuit could quickly switch between 8-bit and 16-bit multipliers in a easy way,which enables byte- word-based multi-media signal processing on the same circuit.The multiplier was implemented with VHDL and synthesized by XST.Post PAR simulation on XC2V4000 showed that the novel multiplier featured high-speed and low resource unitization,compared with reconfigurable multiplier based on distribution law of multiplier.

The paper presents a new strategy for effective evolution of digital hardware by using the on-line adaptive evolution of digital circuits at function level based on the field programmable gate array (FPGA) model. The strategy firstly divides the target digital circuit into several separate sub-units according to its functions, then makes on-line evolutionary design of every sub-unit, and lastly, on-line evolution of the desired circuit was implemented based on the designed sub-units. Thus, the length of chromosome can be reduced and die evolutionary convergence speed can be raised, compared with the circumstance when the gate-level evolutionary method is applied to design of large-scale digital circuits. The on-line evolutionary design of a 4 x 2 multiplier was performed as an example, and the experimental results showed that the digital target circuit was successfully on-line evolved and the convergence speed was increased by about 5 times.

The propagating characteristics of leak signal at low frequencies in buried, water-filled pipes are firstly analyzed. Then the overall design and system integration of a leakage localization system are developed based on the principle of leakage localization and least mean square time delay estimation. The leakage localization system includes the circuits of signal amplifier & low pass filter, leakage data acquisition & communication, digital filtering and leak localization. The leakage signal is converted into 12-bit digital signal, which is read into PC through a communication port. Time delays are estimated at different time section after leakage signals are filtered with proper frequency band filters. Unexpected and abrupt strong disturbances are removed based on the magnitude difference between signal and strong disturbance. Field localization test results show that the system meets the design specifications, and the localization errors between the designed system and reference system are less than 0.5 m, which can satisfy the measurement requirement.

Aiming at eliminating the simultaneous fault of traditional same-structure system caused by common mode interference,different-structure redundant system is designed to get better fault-tolerance ability.Principle and process of different-structure are given based on the knowledge of graph and multi-objective genetic algorithm,then in order to improve fault-tolerant capability,redundant system is designed whose different-structure degree is higher.D flip-flop is taken as an example.The experimental results prove that the performance of different-structure system which is composed of different-sturcture circuits evolved by multi-objective genetic algorithm can obtain better fault-tolerant capability.

Considering the requirements of the electric and automation engineering discipline for computer hardware knowledge and the wide application of embedded systems,the course system structure of the computer hardware series courses is firstly introduced.To adapt to current development of computer technology,the teaching content and the consideration on the reform of teaching system are then expatiated.Finally,the reform practices from the teaching mode,teaching method and experiment teaching are discussed.

Aiming at the applications at high speed,a design and implementation of the LMSTDE algorithm based on FPGA is presented.The paper firstly develops to give the improvement to the LMSTDE algorithm based on the algorithm′s implementation on a single chip of FPGA.Then the overall diagram of the improved algorithm′s implementation is presented.Based on the diagram,the improved algorithm′s implementation on FPGA is carried out with pipeline design and parallel structure,fixed-point decimal fraction data format and hiberarchy & module methods.Finally,the simulation is carried out.The simulation result shows that the time delay of the improved LMSTDE algorithm converges at the true value as the original LMSTDE algorithm.The design and implementation presented is feasible and effective.