汽力装置回汽制动工况下螺旋桨变工况工作过程分析

针对蒸汽动力船舶回汽制动工况下螺旋桨转速经历了0转速状态,而采用传统的螺旋桨模型无法研究该状态的问题,通过对回汽制动工况中螺旋桨的典型动作过程进行分析,建立回汽制动工况中螺旋桨的变工况数学模型。基于Matlab-Simulink环境建立仿真模型,分析回汽制动工况下螺旋桨的动态运行状况,为回汽制动过程下螺旋桨的运行管理提供借鉴。仿真结果表明:在相同的航速下,倒车汽轮机回汽量越大,处于水轮机状态的螺旋桨所能达到的转速就越低;当对全速倒车的耗汽量实施回汽制动时,可以将96.8%最大航速以下的螺旋桨锁制。     

微机控制直通电空制动系统用阀试验研究

介绍了微机控制直通电空制动系统用阀的功能、工作原理及其主要性能指标。结合试验台的测试,阐述了试验台的设计和阀的性能试验方法。对回差与输入上升下降速度、开启时间与充气速度、双向阀换向试验、试验时间控制、泄漏量试验与检测时间的选择等试验结果及其影响因素进行了分析。     

Design and hardware-in-loop implementation of collision avoidance algorithms for heavy commercial road vehicles

An important aspect from the perspective of operational safety of heavy road vehicles is the detection and avoidance of collisions, particularly at high speeds. The development of a collision avoidance system is the overall focus of the research presented in this paper. The collision avoidance algorithm was developed using a sliding mode controller (SMC) and compared to one developed using linear full state feedback in terms of performance and controller effort. Important dynamic characteristics such as load transfer during braking, tyre-road interaction, dynamic brake force distribution and pneumatic brake system response were considered. The effect of aerodynamic drag on the controller performance was also studied. The developed control algorithms have been implemented on a Hardware-in-Loop experimental set-up equipped with the vehicle dynamic simulation software, IPG/TruckMaker®. The evaluation has been performed for realistic traffic scenarios with different loading and road conditions. The Hardware-in-Loop experimental results showed that the SMC and full state feedback controller were able to prevent the collision. However, when the discrepancies in the form of parametric variations were included, the SMC provided better results in terms of reduced stopping distance and lower controller effort compared to the full state feedback controller.     

轨道交通车辆架控制动系统建模及防滑控制研究

制动系统的性能对列车安全运行有重要的影响。在原理分析的基础上,利用AMESim仿真软件对EP2002制动系统气动阀单元(PVU)进行了建模,并通过常用制动和紧急制动仿真验证模型的正确性。在MATLAB/Simulink软件环境下搭建列车动力学模型,并编写防滑控制逻辑,与AMESim气动阀模型进行联合仿真,验证防滑逻辑的有效性。从常用制动和紧急制动仿真结果可以得出,所搭建的EP2002的PVU与真实系统的反应一致,验证了PVU模型的正确性。从防滑控制仿真结果可以看出,所设计的防滑控制逻辑能够达到控制要求,在发生连续滑行时能够达到稳定的防滑效果,为实际列车制动系统的设计和故障的解决提供了有效的模型基础。     

动车组制动系统气动部件可靠性试验台

阐述了动车组气动部件可靠性试验台的设计和系统结构,试验台的适用范围及其试验方法。并简要分析了阀类产品在试验过程中出现的故障及原因。     

新加坡电力蓄电池双能源工程车概述

阐述了南车株洲电力机车有限公司研制的新加坡电力蓄电池双能源工程车的主要技术特点和技术参数,并从设备布置、电气系统、机械系统和空气制动系统等方面详细介绍了技术方案。     

不同药物对反流性食管炎黏膜保护作用的实验研究

目的　用不同药物对混合反流大鼠模型进行干预 ,观察混合反流对大鼠食管黏膜的损伤及西沙比利、萘丁美酮和铝碳酸镁对黏膜的保护作用。方法　健康SD大鼠 16 8只 ,随机分为 4组 :阳性对照组 (Y组 ) ,西沙比利干预组 (P组 ) ,萘丁美酮干预组 (R组 ) ,铝碳酸镁干预组 (D组 )。分别于术后 2 2、2 8、35、4 0周观察食管黏膜的大体和病理变化。结果　术后不同时间Y组的损伤程度均重于其他 3组 (P <0 .0 5 ) ;且Y组Barrett食管 (BE)、重度不典型增生和食管腺癌 (EAC)的发生率均高于其他 3组。P组的损伤程度高于R、D组 (P <0 .0 5 ) ,但BE、重度不典型增生和EAC的发生与R、D组无统计学差异 (P >0 .0 5 )。结论　长期严重的反流性食管炎 (RE)可导致BE、重度不典型增生和EAC ;西沙比利、萘丁美酮和铝碳酸镁对食管黏膜均有一定的保护作用 ,可减少BE、重度不典型增生和EAC的发生 ,但萘丁美酮和铝碳酸镁的效果要优于西沙比利。     

An Active Endoscopy Robotic System for Direct Tracheal Inspection

The development of active endoscopy techniques is one important area of medical robot.This paper designed a new flexible and active endoscopy robotic system for direct tracheal inspection.The mobile mechanism of the robot is based on the inchworm movement actuated by pneumatic rubber actuator.There are five air chambers controlled independently,by adjusting pressures in air chambers,the robot can move in a straight mode or in a bending mode.The inspection sensors and some therapy surgery tools can be equipped in the front of the robot.The prototype was made and its mechanical characteristics were analyzed.The robot could move smoothly in a small plastic tube,and the robot is respectable to be used for inspection in human trachea directly.     

简析气膜煤棚工程的施工

本文介绍了全封闭充气膜结构主要施工方案,原有挡煤墙及防风抑尘墙拆除,新挡煤墙基础施工,气模施工,消防安全设施施工。     

高速动车组智能气动门控系统研究

CRH2型和CRH380A型动车组气动侧拉门有着结构简单、故障率低的优点,但存在车门功能比较单一,硬件升级困难,越来越不能满足列车智能化的需求。文章基于原CRH2型动车组侧拉门的关键技术,重新设计了气动门的车门控制系统,并在原气动控制系统的基础上,增加了电子门控器等电气部件,通过电子门控器控制气动门的开关门动作;优化了车门的设计结构和控制逻辑,增加了网络通信、故障诊断和下载等功能,消除了既有气动门在运营过程中存在的安全问题和功能单一问题。通过台架试验表明,车门达到了设计要求,保证了列车高速运行时的安全与稳定性。