共查询到20条相似文献,搜索用时 164 毫秒
1.
换热器性能测试是换热器设计过程中的重要环节,对其结构优化及性能评估具有重要作用。针对传统的换热器性能测试系统存在试验周期长、组合方案少,自动化水平不高、可重用应用性较差等不足,文章基于工业控制计算机和C++ Builder软件平台开发了换热器性能试验测控与仿真系统。该系统实现了试验工况参数的控制与过程仿真、试验数据的采集记录与分析处理等各项操作的自动化。文章在简要介绍换热器性能测试系统硬件设计的基础上,具体结合系统硬件介绍了利用C++ Builder制作的换热器仿真实验测控系统的方法及过程,最后给出换热器性能测试仿真实验用户界面及仿真实验运行结果。试验结果表明,测控系统具有交互界面良好、使用方便,可靠性高等特点,能够较好地满足换热器性能测试的要求。 相似文献
2.
舵机是导弹控制系统的重要执行机构,为实现对电动及气动多种型号导弹舵机性能的测试,设计开发了一种基于LabWindows/CVI虚拟仪器的测控系统。介绍了该测控系统硬件组成和软件结构流程,软件设计过程中充分利用多线程、数据库等技术,准确快速完成舵机自动化性能测试。应用结果表明:该舵机测控系统工作稳定,测试精度和自动化程度高,满足舵机试验测试精度和技术指标要求,为舵机的性能研究和维修维护提供了良好的测试环境。 相似文献
3.
为了提高纯电动汽车动力系统的工作效率,提出了一种基于电机辅助的纯电动汽车模式切换控制策略。首先,在传统纯电动汽车结构基础上配置一个小功率电机,得到一种双电机型纯电动汽车;其次,在双电机型纯电动汽车各驱动和各再生制动模式下,对其动力系统进行动力学分析和能量平衡分析,得出了系统在各模式下的工作效率模型;然后,以使动力系统工作效率最大为原则,制定了模式切换控制策略,确定了车辆的目标运行模式和两电机的目标转矩;最后,在Advisor仿真平台CYC_NEDC循环工况下,对该模式切换控制策略进行仿真,结果表明,与传统纯电动汽车相比,该控制策略使动力系统的工作效率提高了约6%。 相似文献
4.
5.
6.
7.
8.
为了满足船载统一测控系统沟通无线偏馈射频链路进行遥测误码率测试的要求,进一步构建系统联调联试的动态射频信号环境,设计了船载测控雷达偏馈信号动态控制系统。通过系统监控台手动或自动远程控制位于天线背部中心体的数控衰减器,可实现雷达天线在对冷空的情况下接收偏馈射频信号幅度的变化,也可实现船载测控雷达系统联调过程中模拟目标动态变化情况,进而分析对系统跟踪性能的影响。该系统经过数次海上测控任务的检验,证明其方法科学有效、操作方便快捷、运行稳定可靠,达到了充分检验设备性能、提高任务准备效率的目的。 相似文献
9.
10.
为了充分利用原有机电控制技术试验台,满足机电控制技术课程实践教学的需要,并为先进控制系统研究提供实验平台,改造了原有的机电控制综合实验装置。该装置以电机为实验对象,增加实验对象加载装置,用VC++编写了控制界面,通过PC及PLC两级控制,完成电机特性测试、机电传动系统控制等实验内容。经使用表明,该套实验装置操作简单、开放性好、实战性强。通过本实验台,可提高学生动手能力,完成了工程实践能力的培养。 相似文献
11.
12.
为提高大功率天然气发动机怠速时的稳态和动态效果,以V模式为研究手段,基于一款六缸天然气多点电喷发动机,实现了发动机怠速控制策。首先针对不同的怠速工况设计了不同的目标怠速转速值的计算,并根据发动机特性确定了PI控制模式。利用目标怠速转速和瞬时转速的差值确定不同PI控制参数,通过PI控制调节电子节气门的开度,从而实现对发动机怠速转速的控制。然后根据实际发动机参数搭建了发动机MATLAB/SIMULINK仿真模型,用于对怠速控制策略进行软件在环仿真测试以及PI控制参数预标定。最后在天然气发动机试验台架上对控制策略进行了进一步的试验和标定。试验结果表明:该怠速控制策略,可让发动机转速响应时间控制在1秒左右,转速稳定时间在2秒左右,发动机转速稳态误差控制在±5rpm范围之内,实现了对怠速的良好稳定控制。 相似文献
13.
随着车辆向大型化,高速化的发展趋势,车辆正常行驶制动能量增加,传统的摩擦制动器已经难以满足使用要求,很容易诱发一些故障。电涡流缓速器以其非接触无摩擦,响应时间短,无明显时间滞后,工作时噪声很小,能够提供车辆正常行驶85%的制动功率等优点成为新型的车辆辅助制动系统。本文采用ANSYS软件实现电涡流缓速器转子盘的二维温度场分析,对不同宽度的转筒式电涡流缓速器的温度分布进行数据采集,建立转筒式电涡流缓速器转筒的二维模型,采用虚拟边界法进行简化处理,然后根据系统不同的载荷和约束条件进行温度场控制系统建模。最后本文做了大量的仿真实验,模拟了依据不同的制动力矩,不同的磁路结构以及转子盘温升来分析对汽车制动性的影响。 相似文献
14.
15.
M. S. Lasakov A. O. Polyushkin A. P. Serebrov E. A. Kolomenskii A. N. Pirozhkov I. A. Krasnoshchekova 《Technical Physics》2016,61(4):603-608
We describe the structure of the high-voltage test bench for checking individual insulators and their assemblies with separate control of leakage currents in each insulator. The test bench is mainly intended for preparing the high-voltage block of the spectrometer for the search for the electric dipole moment (EDM) of the neutron. The main part of the bench is the high-voltage source with controllable polarity and voltages up to 200 kV with complex control over parameters. An analogous converter is used in experiment on measuring the EDM of the neutron. We report on the results of testing the new design of the storage chambers of the EDM spectrometer operating with a high voltage; we also test the maximal potentialities of the converter under nearly working conditions; its optimization and calibration are performed. 相似文献
16.
为给 HL-2M 装置 300MVA 脉冲发电机组频繁启停和重大故障时快速停机提供保障,发电机组电气
制动系统采取电气制动和机械制动相结合的运行方式。介绍了 300MVA 脉冲机组电气制动的特殊性,对六相脉冲
同步发电机组电气制动进行了理论分析,确定了电气制动的主回路和控制方案。基于经验证的发电机模型,对正
常工况和极端工况下机组电气制动过程进行了动态模拟,确定了主要设计参数,制动励磁电压和制动电阻分别为
40V 和 0.1Ω。 相似文献
17.
Brake squeal noise has been under investigation by automotive manufacturers for decades due to consistent customer complaints and high warranty costs. J.D. Power surveys consistently show brake noise as being one of the most critical vehicle quality measurements. Furthermore, the development of methods to predict noise occurrence during the design of a brake system has been the target of many researchers in recent years.This paper summarizes the application of complex eigenvalue analysis in a finite element model of a commercial brake system. The effect of the operational parameters (friction coefficient, braking pressure and brake temperature) and wear on the dynamic stability of the brake system is examined. After identifying unstable frequencies and the behavior of the brake system under different conditions, the performance of some control methods are tested. Changes in material properties and the application of brake noise insulators are presented and their effects discussed.The results show that the effect of brake temperature changes the coupling mechanisms between rotor and pad, which in some cases can be useful in order to reduce the instabilities and generated noise. Wear is an operational condition that has an strong effect on the system instability, since stiffness properties of brake pads are influenced by the changes on geometry and on the friction material, leading to high-frequency noise generation when the system is in the end of its lifetime. Application of brake insulators requires a detailed investigation of the system since, for some cases, an increase on the system damping does not balance changes on stiffness, leading the system to instability and noise. 相似文献
18.
Ioan Bica 《Journal of magnetism and magnetic materials》2004,270(3):321-326
The magnetorheological suspension (MRS) brake is of the monoblock type. The main part of the electromagnetic brake is an electromagnet, between whose poles two MRS disks are placed. For distances between disks of 0.65×10−3 m±10%, revolutions of the electric motor, coupled to the electromagnetic brake, ranging between 200 and 1600 rev/min and braking powers of up to 85 W, there are no differences in revolutions between the disks of the electromagnetic brake. For fixed revolutions of the electric motor, the revolution of the parallel disk can be modified continuously by means of the intensity of the magnetic field. In all cases, the quantity of MRS is of 0.35×10−3 kg. 相似文献
19.
This paper examines squeal and chatter phenomena generated experimentally in mountain bike disc brakes. There are two kinds of frictional self-excited vibrations in the bike disc brakes, called squeal with frequency of 1 kHz and chatter with frequency of 500 Hz. In order to reproduce the squeal and chatter, a bench test apparatus using an actual bike was set up to determine the associated frequency characteristics experimentally. The results show the frequencies to be independent of pad temperature and disc rotating speed. Squeal is shown to be in-plane vibration in the direction of the disc surface which is caused by the frictional characteristics having negative slope with respect to the relative velocity in the vibrating system, which includes brake unit, spokes and hub. Chatter is generated within a limited high temperature region. Again, it is frictional vibration in which the squeal and out-of-plane vibration of the disc due to Coulomb friction combine through the internal resonance relation between in-plane and out-of-plane nonlinear vibration caused by the temperature increase of the disc during braking. 相似文献
20.
采用光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)方法建立了高速列车风阻制动板流固耦合二维数值模型,实现了对风阻制动板动态开启过程的数值模拟,分析了风阻制动板的运动规律、受力分布和气动阻力变化规律.结果表明:当车速为300 km/h,最大开启角度为90°时,制动板整个开启过程的动作时间约为0.025 s,满足紧急制动时的快速响应要求;制动板开启初期,板的受力有较大突变且呈梯度分布,易弯曲变形;制动板的整个开启过程中,制动板整体受力水平逐渐提高且保持均匀分布,制动板直角边缘处受力始终较其他部位大,具有良好的增阻效果;最大制动力出现在最大开启角度为75°~85°时,而非垂直开启时,建议将最大开启角度设置为80°以获得最大制动力. 相似文献