电动静液作动器的新型变阻尼级联滑模控制

为改善电动静液作动器（EHA）的动态性能，提出了一种基于新型准自适应变阻尼滑模控制（DV-SMC）和PID控制的级联控制（CC）算法。所提算法将高阶EHA分为液压和机械2个低阶系统，分别对2个低阶系统采用了DV-SMC和双环PID控制策略。DV-SMC方法能够自适应调整滑模面阻尼。在起始阶段采用欠阻尼、末段自适应调节为过阻尼，从而在保证EHA快速性的同时也能够完全抑制超调现象。通过仿真验证了所提算法的有效性，并讨论给出了DV-SMC滑模面最优参数。      

A Hybrid Method Combining Improved K-means Algorithm with BADA Model for Generating Nominal Flight Profiles

A high-precision nominal flight profile,involving controllers′intentions is critical for 4Dtrajectory estimation in modern automatic air traffic control systems.We proposed a novel method to effectively improve the accuracy of the nominal flight profile,including the nominal altitude profile and the speed profile.First,considering the characteristics of trajectory data,we developed an improved K-means algorithm.The approach was to measure the similarity between different altitude profiles by integrating the space warp edit distance algorithm,thereby to acquire several fitted nominal flight altitude profiles.This approach breaks the constraints of traditional K-means algorithms.Second,to eliminate the influence of meteorological factors,we introduced historical gridded binary data to determine the en-route wind speed and temperature via inverse distance weighted interpolation.Finally,we facilitated the true airspeed determined by speed triangle relationships and the calibrated airspeed determined by aircraft data model to extract a more accurate nominal speed profile from each cluster,therefore we could describe the airspeed profiles above and below the airspeed transition altitude,respectively.Our experimental results showed that the proposed method could obtain a highly accurate nominal flight profile,which reflects the actual aircraft flight status.     

植物细胞响应重力变化的Ca2+信号

重力大小的改变(微重力和超重力)可以对植物的生长发育、生理生化特性、细胞超微结构、基因和蛋白的表达等产生广泛的影响,而Ca~(2+)可能在此过程中起信号物质的作用.重力刺激在植物细胞中引发事件的顺序可能是:重力刺激的感受—细胞膜系统张力改变—膜理化特性改变—膜透性、离子转运、膜连接酶活性等改变—Ca~(2+)信号的产生和转导—新陈代谢变化—生理反应.植物对重力水平变化应激响应的至关重要一步是引起细胞内Ca~(2+)分布区域和浓度的变化,这是将细胞外重力刺激转换为细胞内化学信号的关键步骤.由于机械力敏感的C~(2+)通道的活化和Ca~(2+)-ATPase酶活性受到抑制,重力改变时细胞质中自由Ca~(2+)浓度增加,随后Ca~(2+)作为第二信使介导相关酶活性发生改变,最终引起一连串的生理生化反应.本文探讨了重力变化对植物细胞质内自由Ca~(2+)浓度的影响、Ca~(2+)信号的产生机制.以及Ca~(2+)作为次级信号对细胞生理生化过程调节作用的途径和机制,介绍了常用的Ca~(2+)研究方法,并分析了研究的关键点和难点.     

A Test Method for the Static/Moving State of Targets Applied to Airport Surface Surveillance MLAT System

Due to the particularity of its location algorithm,there are some unique difficulties and features regarding the test of target motion states of multilateration(MLAT)system for airport surface surveillance.This paper proposed a test method applicable for the airport surface surveillance MLAT system,which can effectively determine whether the target is static or moving at a certain speed.Via a normalized test statistic designed in the sliding data window,the proposed method not only eliminates the impact of geometry Dilution of precision(GDOP)effectively,but also transforms the test of different motion states into the test of different probability density functions.Meanwhile,by adjusting the size of the sliding window,it can fulfill different test performance requirements.The method was developed through strict theoretical extrapolation and performance analysis,and simulations results verified its correctness and effectiveness.     

Implicit discontinuous Galerkin method on agglomerated high-order grids for 3D simulations

High quality of geometry representation is regarded essential for high-order methods to maintain their high-order accuracy. An agglomerated high-order mesh generating method is inves-tigated in combination with discontinuous Galerkin (DG) method for solving the 3D compressible Euler and Navier-Stokes equations. In this method, a fine linear mesh is first generated by standard commercial mesh generation tools. By taking advantage of an agglomeration method, a quadratic high-order mesh is quickly obtained, which is coarse but provides a high-quality geometry represen-tation, thus very suitable for high-order computations. High-order discretizations are performed on the obtained grids with DG method and the discretized system is treated fully implicitly to obtain steady state solutions. Numerical experiments on several flow problems indicate that the agglomer-ated high-order mesh works well with DG method in dealing with flow problems of curved geome-tries. It is also found that with a fully implicit discretized system and a p-sequencing method, the DG method can achieve convergence state within several time steps which shows significant effi-ciency improvements compared to its explicit counterparts.     

基于事故数据挖掘的AEB路口测试场景

基于国家车辆事故深度调查体系中499例真实的路口事故数据，研究适应于中国的自动紧急制动系统（AEB）路口测试场景。通过基于多元Logistic回归的事故严重程度影响因素分析，提取自动驾驶测试场景的特征要素，构建测试场景。以场景特征要素为聚类参数，采用层次聚类算法挖掘得到了8类路口机动车碰撞典型危险场景，建立了8类适应于中国交通状况的AEB路口测试场景。研究表明:中国的路口场景与Euro-NCAP法规场景有一定的相似性，但较国外更加复杂，其中十字路口的左转与直行冲突是需要重点测试的场景。研究结果可为国内AEB系统的开发和测试提供参考，也可作为建立中国AEB路口测试评价体系的依据。      

测控设备远程集中监控架构设计与实现

对已在使用的具有远程监控功能的测控设备分别采用监控代理,设备的改造套量多,工作量大,易对设备正常运行造成干扰,且风险分散。针对设备远程集中管理建设中存在的这个问题,在分析设备监控现状的基础上,提出了基于集中委托代理来实现测控设备远程集中监控的监控层次和体系架构,并以简单网络管理协议为例给出了实现的方法。结果表明,该架构和方法建设风险集中,易于控制,监控效率高,便于监控信息的二次应用。     

浅谈精益质量管理

通过吸收借鉴精益生产关于现场的管理理念,结合质量管理思想,通过对企业生产、管理等方面的综合分析,提出精益质量管理思路,并针对精益质量管理体系的主要构成和实施层面进行研究探讨。     

基于系统图-AHP的质量目标管理方法研究

提出了基于系统图-AHP的质量目标分解和考核方法.首先介绍了质量目标分解中采用系统图和层次分析法的步骤;进而提出了一种定性定量相结合的基于系统图-AHP的质量目标分解和考核方法,为解决质量目标分解和考核问题提供了切实可行的手段;最后以某公司的年度质量目标分解与考核为例,通过引入目标达成率、目标权重和加权达成率等建立和考...     

基于态势认知的无人机集群围捕方法

无人机集群围捕是智能无人机“蜂群”作战的一种重要任务方式。现有集群围捕方法大多建立在环境已知的基础上，面对未知的任务环境时围捕策略经常性失效。针对此问题，提出了基于态势认知的发育模型，探索一种对环境适应性较佳的围捕方法。首先，对集群围捕行为分解，将围捕离散化；然后，基于深度Q神经网络（DQN），设计一种围捕策略的生成方法；最后，建立状态-策略知识库，并通过大量有效数据的训练，针对不同环境获得不同的策略，对知识库进行发育。仿真结果表明:提出的基于态势认知的发育模型，能够有效适应不同环境，完成不同环境下的围捕。