基于矢量传感器的水下运动目标测向的研究

将基于二维压差式矢量传感器的声压振速联合处理技术应用于水下运动目标测向算法研究中,在小尺寸和低频条件下,实现了对水下运动目标的精确测向。研究了传感器尺寸、信噪比对算法性能的影响,并采用实测辐射噪声对算法性能进行了分析。仿真和实验结果表明,该测向方法具有基阵尺寸小、测向精度高的特点。该研究为水下运动目标的方位估计提供了一种有效的技术途径。     

高精度垂臂的工艺改进设计

汽车四轮定位仪中有一个垂臂零件,它的加工精度要求很高,采用加工中心可以实现,但成本很高。本文采用普通机床,改进了该零件的加工工艺,实现了一次装夹的精密分度达到同样的加工精度,避免加工过程中的工件发生位移,大幅降低了加工成本。     

Mobile Robot Hierarchical Simultaneous Localization and Mapping Using Monocular Vision

A hierarchical mobile robot simultaneous localization and mapping (SLAM) method that allows us to obtain accurate maps was presented. The local map level is composed of a set of local metric feature maps that are guaranteed to be statistically independent. The global level is a topological graph whose arcs are labeled with the relative location between local maps. An estimation of these relative locations is maintained with local map alignment algorithm, and more accurate estimation is calculated through a global minimization procedure using the loop closure constraint. The local map is built with Rao-Blackwellised particle filter (RBPF), where the particle filter is used to extending the path posterior by sampling new poses. The landmark position estimation and update is implemented through extended Kalman filter (EKF). Monocular vision mounted on the robot tracks the 3D natural point landmarks, which are structured with matching scale invariant feature transform (SIFT) feature pairs. The matching for multi-dimension SIFT features is implemented with a KD-tree in the time cost of O(lbN). Experiment results on Pioneer mobile robot in a real indoor environment show the superior performance of our proposed method.     

自主式水下航行器水下回收融合引导技术方案及算法

[目的]为解决母艇携载的自主式水下航行器（AUV）在水下自主回收和对接的问题,基于惯导（INS）、声学超短基线定位（USBL）、光学等信号引导的多源数据融合,提出一种面向移动平台的AUV水下回收对接引导方法。[方法]为此,设计融合多传感器信息的扩展联邦卡尔曼滤波器,采用分散滤波并再经信息融合方法以提高滤波精度。分别以INS和USBL及光学探测信号作为子滤波器的输入信息,结合AUV水下回收对接过程中的5个阶段分别建立运动方程,最终得到适用于移动平台搭载的AUV水下对接引导系统的多源数据融合导航算法。[结果]仿真结果表明,所提方法具有可行性、系统鲁棒性和控制精度,[结论]可满足母艇水下回收作业对接的工程要求,以及作为AUV水下自主回收操作的技术参考。     

本土化语境下的汽车外观设计研究 ——以红旗H5为例

近年来,我国的汽车工业化逐渐完善,各大自主车企的汽车设计无论是在外观内饰设计上还是硬件设施方面都取得了较为显著的进步.科技的进步,汽车消费市场的飞速发展,使得全球汽车的功能、工艺以及在技术层面上逐渐走向趋同化,汽车外观造型将在整个汽车设计中占有举足轻重的分量,汽车的造型除了艺术层面的审美需求和技术层面的规范以外,更应该...     

上海国产化A型地铁列车

介绍了上海市"科教兴市"项目——自主知识产权的国产化A型地铁列车的总体设计特点,对车辆总体运行环境及基本参数、车体、电气牵引控制、制动、转向架和其他辅助系统等几方面进行了综述。     

Time reversal damage localization method of ocean platform based on particle swarm optimization algorithm

The traditional time reversal is considered a promising approach for non-destructive testing and health monitoring of key region and structure, but it is considerably time consuming. This paper presents a time reversal damage localization method, based on particle swarm optimization algorithm, which is capable of improving the real-time performance of health monitoring in ocean platform. Firstly, the virtual focusing model of time reversal is constructed, and a succinct expression of virtual focusing for sensor pairs is proposed. Then, on the definition of the evaluation index, the PSO based time reversal algorithm is proposed, and the proper coefficients is given. Finally, the finite element simulation and experimental case validate that the proposed method is capable of find the damage location within limit iterative steps. Thus, the proposed method is a hopeful method for online monitoring and damage localization of large sized structure.     

Towards lane-level traffic monitoring in urban environment using precise probe vehicle data derived from three-dimensional map aided differential GNSS

Today's urban road transport systems experience increasing congestion that threatens the environment and transport efficiency. Global Navigation Satellite System (GNSS)-based vehicle probe technology has been proposed as an effective means for monitoring the traffic situation and can be used for future city development. More specifically, lane-level traffic analysis is expected to provide an effective solution for traffic control. However, GNSS positioning technologies suffer from multipath and Non-Line-Of-Sight (NLOS) propagations in urban environments. The multipath and NLOS propagations severely degrade the accuracy of probe vehicle data. Recently, a three-dimensional (3D) city map became available on the market. We propose to use the 3D building map and differential correction information to simulate the reflecting path of satellite signal transmission and improve the results of the commercial GNSS single-frequency receiver, technically named 3D map-aided Differential GNSS (3D-DGNSS). In this paper, the innovative 3D-DGNSS is employed for the acquisition of precise probe vehicle data. In addition, this paper also utilizes accelerometer-based lane change detection to improve the positioning accuracy of probe vehicle data. By benefitting from the proposed method, the lane-level position, vehicle speed, and stop state of vehicles were estimated. Finally, a series of experiments and evaluations were conducted on probe data collected in one of the most challenging urban cities, Tokyo. The experimental results show that the proposed method has a correct lane localization rate of 87% and achieves sub-meter accuracy with respect to the position and speed error means. The accurate positioning data provided by the 3D-DGNSS result in a correct detection rate of the stop state of vehicles of 92%.     

富康轿车进气阀座刀具国产化改进

本文针对富康轿车进气阀座进口的三个成型锥面精铰复合刀寿命低现象 ,对切削图形不合理、切削力的影响因素和振动的起因等方面进行了分析和研究。     

人乳头瘤病毒16型(湖北株)E7蛋白在NIH/3T3细胞中的表达和定位

目的　将带有人乳头瘤病毒 1 6型 (湖北株 )E7基因的真核表达载体 pL(E7 HB)SN导入NIH/3T3细胞进行瞬时表达。方法　重组质粒转染 3T3细胞通过DNA 磷酸钙共沉淀法 ;E7基因表达的检测采用RT PCR和间接免疫荧光实验。结果　E7基因导入真核细胞后能有效转录并表达E7蛋白 ,通过免疫荧光染色可看到E7蛋白主要定位在胞浆中 ,细胞核中也有 ,但量较少。结论　这可能和湖北株HPV1 6E7基因发生突变有关。