基于隐马尔可夫模型的语音识别技术在载人航天器上的应用

利用嵌入式平台构建了基于隐马尔可夫模型（Hidden Markov Model,HMM）技术的载人航天器语音识别系统,并针对载人航天器特殊的噪声背景和声学训练,对传统语音端点检测算法进行了改进。通过试验在嵌入式运行环境下实现了指令发送、文字输入等功能,证实该系统适应航天员的口音和发音习惯,可对连贯自然发音方式的命令进行识别,能够满足航天员及任务使用需求。     

基于改进的速度同步控制的电液负载模拟器

对地面半实物加载仿真实验中存在的"多余力"问题进行分析和研究。首先建立了电液加载系统的数学模型,提出"多余力干扰系数"的概念,并给出定义方法。利用多余力干扰系数对多余力"成分"进行定量分析,理论分析传统"速度同步控制"抑制多余力的机理以及存在的问题,并提出了改进方法。在传统"速度同步控制"的基础上,提出利用舵机和加载系统的速度差对"多余力"进行二次抑制。实验结果验证了改进方案的有效性。基于改进方法,电液负载模拟器取得了理想的动态加载效果,"多余力"抑制能力较传统的"速度同步控制"方法提高了25%以上。     

回热循环微型燃气轮机非线性数学模型

建立了回热循环微型燃气轮机非线性动态模型,并考虑模型通用性采用压气机、回热器、透平的变工况解析通用特性建立了静态模型.根据设计参数进行数学模型的实例化,提出解析特性系数确定方法和计算机仿真实现的迭代次序.结果表明:静态特性仿真结果与Capstone C30实际数据之间存在微小偏差,通过更详细的参考数据校正特性解析公式系数可获得与实际数据更好的一致性;采用保持透平进气温度不变的最佳运行方式,空载到满载的动态时间为100s左右,回热器金属壁面平均温度由空载时750K降低到负载时670K.      

航天器任务规划中资源约束的可分配处理方法

面对深空探测过程中环境的不确定性和扰动,航天器需要利用任务规划技术实现自主控制。航天器应用规划算法时,需要考虑到执行活动时满足的时间约束和资源约束。通过分析资源约束之间的关系,提出了可重复资源在规划执行时的可分配处理方法,和判断资源变量是否满足的可分配性条件。通过航天器仿真算例,验证了可重复资源的可分配处理方法在规划执行时的有效性。     

An attack-immune trusted architecture for supervisory aircraft hardware

With the wide application of electronic hardware in aircraft such as air-to-ground communication, satellite communication, positioning system and so on, aircraft hardware is facing great secure pressure. Focusing on the secure problem of aircraft hardware, this paper proposes a supervisory control architecture based on secure System-on-a-Chip (SoC) system. The proposed architecture is attack-immune and trustworthy, which can support trusted escrow application and Dynamic Integrity Measurement (DIM) without interference. This architecture is characterized by a Trusted Monitoring System (TMS) hardware isolated from the Main Processor System (MPS), a secure access channel from TMS to the running memory of the MPS, and the channel is unidirectional. Based on this architecture, the DIM program running on TMS is used to measure and call the Lightweight Measurement Agent (LMA) program running on MPS. By this method, the Operating System (OS) kernel, key software and data of the MPS can be dynamically measured without disturbance, which makes it difficult for adversaries to attack through software. Besides, this architecture has been fully verified on FPGA prototype system. Compared with the existing systems, our architecture achieves higher security and is more efficient on DIM, which can fully supervise the running of application and aircraft hardware OS.     

一种图像缩放算法的SoC协同加速设计方法

针对无人机自主着陆的跑道检测、识别、跟踪等视觉算法中需要对大量图像进行缩放处理以便后续计算,但又对实时性要求比较高的情况,根据输入输出像素点的映射关系提出了一种适用于硬件加速的图像缩放算法,简化算法结构的同时利用现场可编程门阵列进行模块硬件功能的设计对算法加速,并采用软硬件协同的体系结构搭建实时图像处理系统。实验结果表明,该缩放算法处理精度高、耗时少,且用硬件逻辑实现后,可以进一步提速171倍,硬化后的系统可以通过摄像头获取图像数据,实时处理后在显示器中显示,达到30帧/s的处理速度,可以应用于实时性要求较高的图像处理算法中。      

基于无向图的SoC软硬件划分方法

软硬件划分是SoC软硬件协同设计中的重要步骤之一。针对软硬件划分问题,提出一种基于无向图的软硬件划分方法,将软件成本和硬件成本设定为网络图的节点,将功能模块间的通讯成本设定为无向的边,从而将芯片的软硬件划分问题归结为基于无向图理论的多目标优化求解的问题。仿真结果证明,该方法在算法效率上优于GA算法和KL算法。并且设计研制了FPGA测试平台,实现软硬件并行开发,提高了基带芯片开发的效率。以BDS/GPS双模基带芯片为例,对本方法进行了具体实施,为基带芯片的软硬件划分设计提供了理论依据。     

Multi-objective evolutionary design of selective triple modular redundancy systems against SEUs

To improve the reliability of spaceborne electronic systems,a fault-tolerant strategy of selective triple modular redundancy(STMR)based on multi-objective optimization and evolvable hardware(EHW)against single-event upsets(SEUs)for circuits implemented on field programmable gate arrays(FPGAs)based on static random access memory(SRAM)is presented in this paper.Various topologies of circuit with the same functionality are evolved using EHW firstly.Then the SEU-sensitive gates of each circuit are identified using signal probabilities of all the lines in it,and each circuit is hardened against SEUs by selectively applying triple modular redundancy(TMR)to these SEU-sensitive gates.Afterward,each circuit hardened has been evaluated by SEU Simulation,and the multi-objective optimization technology is introduced to optimize the area overhead and the number of functional errors of all the circuits.The proposed fault-tolerant strategy is tested on four circuits from microelectronics center of North Carolina(MCNC)benchmark suite.The experimental results show that it can generate innovative trade-off solutions to compromise between hardware resource consumption and system reliability.The maximum savings in the area overhead of the STMR circuit over the full TMR design is 58%with the same SEU immunity.     

飞控襟翼硬件仿真系统的设计及应用

以飞机控制系统的设计要求为依据设计飞控襟翼硬件仿真系统,该系统是参照真实飞控襟翼系统的功能和接口要求,采用基于数字仿真扩展模拟电路接口的硬件仿真系统。其与真实襟翼具有相似功能、相同接口、完全可以替代真实襟翼完成相关试验。试验结果表明:该系统为飞控襟翼试验的圆满完成提供有效的保障。     

CDMA系统中的扩频序列及其软件实现

扩频序列的构造和设计是CDMA系统与扩频通信系统中的关键技术之一。目前的许多扩频序列研究成果都是使用有限域上的迹函数来给出，这对工程应用十分不便。文章首先总结了目前国内外在扩频序列研究领域所取得的重要成果；然后重点讨论了有限域上的运算及迹函数的软件实现，并以此为基础研究了GMW序列和No序列的软件实现；最后总结了Gold序列、Kasami序列、Bent序列、交织序列和作者提出的一类序列的研究成果与实现的有关文献。