Two-way中继系统的中继选择算法分析

为了提升双向AF中继系统总速率和降低系统中断概率,提出了一种最小中断概率的中继算法MOP,介绍了现有的两种中继选择算法,利用通信系统的性能指标(信噪比、中断概率、信道容量)展开分析。仿真结果表明,所提出最小中断概率中继选择算法可明显降低系统中断概率,在提升系统总速率的性能与最大化容量中继算法接近,有效地改善了系统性能。     

基于Android的科目三模拟考试系统

基于Android的科目三模拟考试系统把驾驶员考试从车载电脑迁移到便捷的Android手机智能平台,在保证模拟考试质量的前提下降低了驾校的硬件成本。实践证明使用科目三模拟系统能够提高考试合格率、减少学员训练时间、提升驾校招生率且能够提高训练车辆的使用效率。     

Performance of Two‐User Two‐Way Amplify‐and‐Forward Relaying Systems with Scheduling

In this paper, we study scheduling schemes for two‐user two‐way wireless relaying systems. Two transmission modes are considered: point‐to‐point direct transmission and two‐way amplify‐and‐forward relaying. An optimal scheduling scheme that opportunistically selects the best transmission mode for each user is proposed to minimize the sum bit error rate (BER). The performance lower bound of the optimal scheduling scheme is analyzed, and closed‐form expression of the lower‐bound BER is derived. However, for optimal scheduling, the scheduler requires the knowledge of channel state information (CSI) of all links. To reduce the feedback information of CSI, we also propose a suboptimal scheduling scheme that selects the transmission mode using only the CSI of two direct links. Simulation results show that there are 4 dB to 8 dB gains for the proposed optimal and suboptimal schemes over the fixed direct transmission and fixed two‐way relayed transmission scheme. The performance gap between the optimal and suboptimal scheduling schemes is small, which implies a good trade‐off between implementation complexity and system performance.     

使用航空深弹驱赶潜艇建模与仿真

非战争时期,驱赶可疑潜艇是航空深弹的主要作战任务,也是其自身特点和优势体现.首先,在分析驱赶潜艇作战原则的基础上,利用航空深弹爆炸威力模型和潜艇壳体抗冲击模型,给出了深弹起爆时距离目标的安全半径和最大有效半径;然后,根据投弹散布模型和目标定位模型,提出了驱赶潜艇目标的投弹瞄准点位置,通过权衡完成驱赶目标任务概率和对目标潜艇造成毁伤的概率,确定投弹瞄准点.最后,针对声纳系统和磁探仪的不同目标定位条件,仿真分析了具体算例.仿真结果表明,较高的投弹精度和水下目标定位精度能更好地控制作战效果.     

暴雨天气情况下变换车道的预警算法

根据南方特殊气候,以及当前多数车辆的预警系统因基于车辆参数而误报率增加的情况,建立了一种具有驾驶员生物特性以及车辆未来轨迹预测的预警算法;在暴雨情况下,驾驶员的前方,侧方视线会受到不同程度的限制,后视镜功能因结雾而基本丧失,加上路面因积水而导致阻力减少,驾驶员因对于车辆的控制程度降低而出现车辆偏离正常行驶轨迹而变换车道的情况;而传统的预警系统因雨天因素误报率也会大大增加;针对上述问题,提出一种基于未来轨迹预测以及驾驶员意图判断的变换车道预警算法.     

基于FTA和AMESim的四通均流阀可靠性提升研究

四通均流阀能够将入口流量均等分成四路,驱动四路不同的负载保证同步动作。采用故障树分析法(Fault Tree Analysis,FTA),对该阀件的失效模式进行研究;通过AMESim仿真,进一步对故障模式进行验证,提出相应的改进措施,并试制样机进行可靠性试验,提高了阀件的性能,对其他阀件的可靠性设计有一定的借鉴作用。     

Tunnel lane‐positioning system for autonomous driving cars using LED chromaticity and fuzzy logic system

Currently, studies on autonomous driving are being actively conducted. Vehicle positioning techniques are very important in the autonomous driving area. Currently, the global positioning system (GPS) is the most widely used technology for vehicle positioning. Although technologies such as the inertial navigation system and vision are used in combination with GPS to enhance precision, there is a limitation in measuring the lane and position in shaded areas of GPS, like tunnels. To solve such problems, this paper presents the use of LED lighting for position estimation in GPS shadow areas. This paper presents simulations in the environment of three‐lane tunnels with LEDs of different color temperatures, and the results show that position estimation is possible by the analyzing chromaticity of LED lights. To improve the precision of positioning, a fuzzy logic system is added to the location function in the literature [1]. The experimental results showed that the average error was 0.0619 cm, and verify that the performance of developed position estimation system is viable compared with previous works.     

基于SSD的多因素融合的驾驶疲劳检测研究

为了降低因疲劳驾驶而导致的事故发生率,提出一种利用卷积神经网络与人脸特征点、疲劳判定指标相融合的方法,共同构建疲劳驾驶检测模型。首先利用SSD（Single Shot MultiBox Detector）网络定位驾驶员的眼睛与嘴巴区域,VGG16 网络学习这两个区域所包含的疲劳特征;同时再结合人脸68特征点、眼睛纵横比（Eye Aspect Ratio, EAR）和嘴巴纵横比（Mouth Aspect Ratio, MAR）共同判定驾驶疲劳状态。最后,在相同测试集下分别计算SSD算法和Faster-RCNN算法的平均精度均值mAP;在YawDD数据集上应用此模型;并通过模拟驾车环境来验证此模型的可行性。实验结果表明,SSD算法要优于Faster-RCNN算法,并且此模型在YawDD数据集上的检测准确率约达97.2%,摄像头也能对驾驶员的状态进行实时检测。此模型对疲劳状态的检测十分有效,可在一定程度上降低因疲劳驾驶而导致的事故发生率。     

未来信息化战场及信息化导弹武器装备构想

通过对未来信息化战场的结构组成、作战模式、战场信息分类和应用及导弹武器装备在其中扮演角色的论述,提出导弹武器信息化的意义和内涵,并详细叙述了导弹武器装备信息化的途径和手段.     

内能源转管武器喷管气流数值计算

提出了一种内能源转管武器实现高射频低后坐的新型驱动技术--喷管气流反推驱动技术.建立了喷管气流反推驱动模拟实验装置的喷管数值计算模型,考虑导气管火药气体对身管流出流进,数值计算取得的结果与实验基本一致.