基于时空域集成判决的微小运动目标检测方法

提出了一种基于时-空域集成判决的序列图像中微小运动目标检测方法。首先,将背景杂波抑制后的残差图像沿时间轴进行累加,形成组合帧,在组合帧中经过二元假设门限判决,检测出疑似目标;然后,只对疑似目标按可能的运动方向进行空域能量集成;最后,对目标轨迹进行统计判别。算法的性能分析和实验仿真结果表明,该方法在保证较高检测概率的同时,大大减少了运算量,有利于实时实现。     

An inchworm mobile robot using electromagnetic linear actuator

The capability of motion is one of the important aspects for a micro-robot to fulfill its given tasks. Micro-autonomous systems usually require large force, large displacement and less power consumption. Among different actuation schemes, electromagnetic actuator shows the benefit in a combination of force, displacement and cost effective control. A bristle-based inchworm mobile robot using a short stroke electromagnetic linear actuator is described in the paper. The main body and movable unit of the robot are joined by using a sealed bellows and the bristle legs are designed so that it can operate both on plane surfaces and in liquid. The actuator designed for the robot is a tubular type linear machine with an overall size of Φ7 × 10 mm. The key dimensions of the actuator were determined through magnetic field analysis to achieve optimum force output and necessary travel stroke within the limited space. The predicted actuation force of the actuator is 20 mN and the stroke length is 1.2 mm. Two working prototypes of the actuator were constructed and the performance tests show the effectiveness of the design. A sensorless control scheme with a novel start-up strategy for the designed actuator was developed based on the robotic system modeling and the analyzed results show the satisfactory performance of the system.     

Phase Transformation and Optimized Growth of TFA-MOD REBa2Cu3O7-x Films for Coated Conductors

Several types of REBa2Cu3O7-x (REBCO, RE=Y, Ho etc.) films are prepared on single crystal substrate LaAlO3 by TFA-MOD method. The phase transformation and optimized growth conditions in the crystallization are studied. Compared with SmBCO and GdBCO, high quality YBCO and HoBCO films are relatively easy to produce. It is revealed that the YBCO grains can form at low temperatures such as 730℃ during the initial heating ramp. With a high heating rate of 20 K/min and a low oxygen pressure of 100 ppm, the optimum growth temperature is around 780℃, at which the films show a Jc value of 2.88 MA/cm2. Further decrease of the heating rate may produce the highquality YBCO film with a higher Jc of 3.65 MA/cm2. The temperature dependence of resistances in various magnetic fields up to 9 T shows that the present TFAMOD YBCO and HoBCO films have similar superonducting transition temperature and magnetotransport properties.     

城市客车信息集成控制网络测试技术研究

本文针对城市客车信息集成控制网络,确定了网络的性能指标。采用一种新的车载网络总线监控工具——Vehicle Spy3,结合半实物仿真技术,构建了城市客车信息集成控制网络的测试平台,从测试环境构建、测试步骤和测试过程中的主要问题等方面研究了城市客车信息集成控制网络的测试方法,结合实例车型对城市客车信息集成控制网络的测试技术进行了实验。实验结果表明,所研究的城市客车信息集成控制网络的测试技术可行,适应工程需要。     

应用于高速信号传输系统的多路选择器

提出了一种能够传输高速信号的多路选择器,并为其设计了一种低失真、宽带模拟开关.所提出开关的栅源过驱动电压由nMOS和pMOS的开启电压之和决定,并能够确保输入变化时,开关的栅源电压与阈值电压之差(VGST)保持恒定,从而基本消除了体效应的影响.采用TSMC 0.18μm CMOS工艺,HSPICE仿真结果表明,输入信号在0.3～1.7V之间变化时,开关的VGST基本保持恒定,其-3dB带宽大于10GHz,当输入频率为1GHz时,其无杂散动态范围为67.11dB;开关的开启时间为2.98ns,关断时间为1.35ns,确保了多路选择器的break-before-make特性.该结构可应用于高速信号传输系统中.     

咪唑在氮气中的热稳定性及其应用

研究了预焊剂咪唑在氮气中的热稳定必一类在时延变参数并在ＰＣＢ的焊接工艺中首次使用Ｎ２作为热处理的氮氛。结果表明：改革后的工艺操作简便，咪唑预焊抗氧化性能及可焊性能优良，符合ＰＣＢ可焊性要求，值得大力推广。     

Dependence of the linewidth enhancement factor on the number of compressively strained quantum well in lasers

We have systematically studied the well number dependence of the linewidth enhancement factor in strained quantum-well (QW) lasers and have demonstrated experimentally that the linewidth enhancement factor can be reduced from /spl sim/9.4 to /spl sim/2.0 by increasing the number of compressively strained QW's from 2 to 8. This behavior is primarily due to an increase in the differential gain with the number of QW's.     

高功率二极管泵浦固体激光技术和应用前景的分析

文章对高功率二极管泵浦固体激光器的若干关键技术，包括激光二极管和增益介质，泵浦，耦合和冷却技术，以及光学谐振腔等作了详细的分析。     

H.26L性能分析与算法优化

在相同的码率控制策略的最优参数配置下，对H．26L，MPGE－4 ASP校验模型系统进行计算机仿真，实验表明，对于CIF和QCIF格式的图像，在压缩效率上H．26L要高于MPGE－4 ASP。相同峰值信噪比条件下，H．26L目标码率约为MPEG－4 ASP的1／3－1／5，然而H．26L的运算复杂也远高于MPEG－4 ASP。本文采用整像素和亚像素运动估值的快速算法，使运算复杂度的约降低到原来的1／3。     

提高激光三角法测量精度的新方法

激光三角法是一种几何测量的重要方法,目前已广泛用于测量位移和三维面形,但这测量系统的测量精度不高,一个主要的问题就是光源光强不稳定;本文提出用光学双稳装置来稳定激光光泊的光强,并用于测量金属板材,实验结果：将光学双稳装置用于激光三角法使系统的测量精度大大提高。