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1.
The ignition system in automobiles is a main source of electromagnetic interference (EMI), because the electromagnetic emission from the system has the characteristics of high-energy and wide-bandwidth. A method for EMI prediction based on its components’ circuit models is presented. First, the characteristics of the components are analyzed and the equivalent circuits are drew; then, the parasitic parameters of the electromagnetic device are extracted from measurement, analytical solution or finite element method (FEM); and finally, the circuit model of the whole ignition system model in high frequency condition is established. This model is verified by the measurement and simulation results in time domain and in frequency domain.  相似文献   

2.
Electromagnetic radiation, which is caused by the engine ignition system, is the most powerful electromagnetic interference (EMI) source in the vehicles, as well as the main reason of most electronic control unit (ECU) malfunction. In order to reduce interference from ignition noise on ECU, we use optical isolation technology to isolate electrical connections between the interference source and the control circuit. The formation mechanism of the ignition system EMI is analyzed. The possibility of suppressing ignition system EMI with optical isolation technology is discussed. Then, as a result we design an experimental platform of suppressing ignition system EMI. The experimental results show that the effect of suppressing ignition noise, in 20~100 MHz frequency band, is obvious after applying optical isolation circuit. It can address the issue of automotive EMC.  相似文献   

3.
4.
By analyzing the inherent uncertainties, discrete uncertainties and external environmental uncertainties, a dual-feedback control strategy and the dynamic scheduling method are proposed to solve the dynamic scheduling problem of vehicle air-conditioning assembly shop under uncertainty. Considering the reentrant constraint, equipment capacity constraint, and time discrete constraint etc., the multi-objective scheduling model of vehicle air-conditioning assembly shop is set up,taken the earliness/tardiness, process time, production cost and quality loss as optimization objectives. According to the characteristic of the model, sectional chromosome encoding, crossover operator and mutation operator are designed to prevent the generation of illegal solutions and improve efficiency of the algorithm. An example is given to prove the feasibility and validity of the approach.  相似文献   

5.
By combining a driver model, a vehicle system dynamics model, and a vehicle lateral stability control system, the performance of the driver vehicle road closed loop system through a pylon course slalom test was simulated. The simulation was done in accordance with the GB/T6323.1-94 standard. Vehicle stability control system effectiveness was evaluated by measuring the mean maximum yaw rate and the mean maximum steering wheel angle. The simulation results showed the slalom test value with lateral stability control was approximately 4% higher than without a stability control system. This indicates the controlling system improves vehicle handling stability.  相似文献   

6.
作物抗寒性鉴定原理与鉴定技术体系的研究   总被引:11,自引:0,他引:11  
赵玉田 《作物学报》1993,19(5):420-428
该项研究采取指标定性与定量,分析与综合,反复测定与田间验证结合的方法,建立和完善利用多种鉴定方法(田间多点联合鉴定、模拟逆境筛选和实验室测定)及综合指标评价作物抗寒性的技术体系,并提出了筛选抗逆“源”的方法。同时概述了小麦寒胁迫膜蛋白的种类、变化与抗冻性的关系以及介绍了作物抗寒性分子基础的探索。  相似文献   

7.
许多研究指出摄取富含茄红素的食物具有降低多种癌症的发生率,如前列腺癌、肺癌等[1,2]。在茄红素体外试验中,最常使用四氢呋喃(tetrahydrofuran;THF)作为溶剂,但THF结构不稳定,极易氧化,且具有细胞毒性,因此易造成茄红素体外试验之干扰[3 ̄5]。本实验拟使用胎牛血清(fetalbovineserum;FBS)作为载体,我们认为FBS中的脂蛋白(lipoprotein)可以增加茄红素稳定性并促进细胞的吸收效果。  相似文献   

8.
With a focus on a Changan hybrid electric vehicle (HEV) with an integrated startor and generator (ISG), strategies for braking force distribution and coordinated pressure control are put forward, and a dynamic braking control model is constructed for off  相似文献   

9.
调查研究表明,冬小麦条锈病发生晚的麦田,病叶主要分布在上部,与早发麦田相比,同部位叶片发病轻,因而形成的本田菌源量低,不利于后期小麦条锈病暴发,控病效果明显。因此对早发麦田要早期挑治和中期控制,对晚发麦田要中期控制,阻止外部菌源的落户和本田菌源的形成,有效减轻后期发病程度, 中度以上发病年份,齐穗扬花期普防病田  相似文献   

10.
In order to resolve the problems of the traditional interference temperature estimation methods, such as unclear spatial characteristics, inaccurate estimation of spatial distribution, and the insufficient use of spectrum resources, this paper proposes an estimation method which utilizes the interference temperature sample values obtained by wireless sensors distribute in space to estimate the interference temperature in the total area. This method makes use of the geo-statistical interpolation method of Kriging to calculate the interference temperature data and obtain the 3-dimensional distribution of the interference temperature in the area. Kriging interpolation method is based on the variogram and structure analysis theory, makes optimal estimation of the variables in area. Simulation results demonstrate that the proposed method can estimate the spatial distribution of interference temperature in the interested area more accurately and the spatial spectrum utilization is improved.  相似文献   

11.
为了寻求一种适合交直流同塔架设线路的无线电干扰与可听噪声计算方法,从理论上分析了混合线路表面场强的特点,利用线性叠加原理求出混合线路表面场强,并结合晴天和雨天对交流和直流线路电晕程度的不同影响,提出在同一种天气状况下计算交直流线路无线电干扰与可听噪声。用3种计算无线电干扰与可听噪声的方法,分晴天和雨天情况进行计算比较,结果表明3种方法中BPA修正公式计算值最大,该方法可视为目前计算交直流同塔线路无线电干扰与可听噪声的有效方法。  相似文献   

12.
This paper analyzes the deep reasons why the benefits are always poor though China has controlled the vehicle exhaust for more than ten years, as well as a successful experience of the developed countries. Contrasting the deficiencies of the previous Air Pollution Control Law and advantages of the present Air Pollution Control Law , the paper indicates the organization structure and management system of the EPA are not entirely eligible for the tasks though the new law entitles environmental administrations to strengthening the exhaust control. It calls for that, according to principle that a structure results in a function, China must establish the management system of vehicle emission control in metropolises as soon as possible. So we can implement this law and improve urban air quality that has deteriorated due to vehicle exhaust. This paper puts forward organization form, functions, tasks and effect of this system.  相似文献   

13.
Automatic mechanical transmissions (AMT) are suitable for use in heavy duty vehicles. Bench testing is an important task of the research and development. Many objectives, such as AMT performance testing, matching AMTs with engines, and optimizing control rules, can be achieved through bench testing, thereby laying a foundation for AMT application. An AMT testing bench is built up based on a developed AMT. By analyzing the performance requirements of AMT bench testing for heavy duty vehicles, a testing controlling system scheme is proposed and methods of data acquisition and communication are analyzed. Control methods for actuators are proposed based on analyzing the characteristics of AMT actuators. A testing control program for AMT bench testing is developed based on the Delphi platform. The entire bench testing system possesses advances test functions.  相似文献   

14.
汽车转弯自动照明控制系统数据采集滤波方法   总被引:1,自引:0,他引:1  
为了减少汽车转弯自动照明控制系统数据滤波处理中的延时,在滑动中值滤波方法基础上,提出了一种带补偿的限幅滑动中值滤波算法,通过补偿的方式跟随信号的变化趋势。该算法通过2个步骤完成滤波,先对数据进行带补偿方式的限幅处理,再进行滑动中值滤波处理。该算法综合了滑动中值滤波法的实时性以及限幅滤波法对偶然性干扰滤除的有效性,实现更准确的滤波。仿真与实测结果表明,与滑动中值滤波方法相比较,改进后的算法滤波能够实时地滤除数据中的干扰,处理时间可减少62%,滤波效果较好,且速度信号的数据滞后时间较短,实时性较高,满足系统设计要求。  相似文献   

15.
An improved predictive control method is presented to compensate the random time delay in the networked control system. The feedback time delay is compensated by predictive controller based on softened increment input strategy. The forward time delay is unknown for controller, so an extra feedback loop is added to compensate the delay by estimating the error between the actual control signal effected on plant and the output of controller in historical moment. For the controlled system with unknown or slowly varying parameters, the networked feedback correction algorithm is discussed based on a modified recursive least-squares identi cation algorithm. The system stability is analyzed and the simulation results show that the time delay in the networked control system can be accurately compensated. The excellent network performance is ensured with this strategy.  相似文献   

16.
药渣及秸秆替代基质中草炭进行烤烟漂浮育苗研究初报   总被引:12,自引:1,他引:11  
用堆捂腐熟的药渣和玉米秸秆完全替代烤烟漂浮育苗基质中的草炭,形成9个基质配方。通过与成品商用基质进行对比育苗试验,开展了用腐熟药渣和玉米秸替代草炭作烟草漂浮育苗基质的可行性研究。结果表明:用药渣和腐熟玉米秸来代替草炭作烤烟漂浮育苗基质是完全可行的;粗药渣60%+细药渣20%+珍珠岩20%和细药渣60%+腐熟玉米秸20%+珍珠岩20%的二个替代处理的综合育苗性能与对照最为接近,基本具备了作为烤烟漂浮育苗基质的条件,所育烟苗均能达到壮苗标准要求,但烟苗地上部分和地下部分的协调程度还不及对照,这一点需要进一步的研究加以改进。  相似文献   

17.
试论农林院校创新型人才培养模式的建构及路径选择   总被引:4,自引:0,他引:4  
知识经济时代,创新成为社会发展主旋律。面对前所未有的挑战,必须培养大批具有创新意识、创新精神和实践能力的创新型人才。诠释了农林院校创新型人才培养模式内涵、建构原则及其紧迫性,探析了目前农林院校创新型人才培养中存在的主要问题及模式建构之路径选择,对指导农林院校创新型人才的培养具有重要理论意义和实践价值。  相似文献   

18.
邓恩桉再生系统的研究   总被引:1,自引:1,他引:0  
邓恩桉生长速度快、耐寒能力较强,近年来已成为中国南方地区的重要造林树种,但其种子主要依赖进口且价格昂贵,因此进行再生体系的研究对解决种苗问题具有重要意义。本研究以种子和腋芽为外植体建立了邓恩桉再生体系,研究结果如下:采用无菌播种后萌发产生的胚轴和子叶进行体细胞胚胎发生途径培养,诱导和分化的最佳培养基配方为1/2MS+6-BA0.5+NAA0.2+IBA0.5,芽继代培养周期25天,扩繁系数3.1;采用邓恩桉腋芽进行的器官发生途径培养,诱导和分化的最佳培养基配方为1/2MS+6-BA0.5+NAA0.2+IBA0.5,继代培养周期和扩繁系数与胚胎发生途径基本一致。将通过2种途径繁殖的芽苗转接到生根培养基1/2MS+NAA0.2+IBA0.5上,7天后陆续生根,25天后生根率70%~71%。试验结果为邓恩桉组培快繁及工厂化育苗提供了有力的理论和实践基础。  相似文献   

19.
彭涛  柳新伟 《中国农学通报》2010,26(17):370-373
城市化进程对河流系统结构、过程与功能产生显著影响,部分引起河流生态系统退化。本文综述了在城市化过程中影响河流系统的各种因子,认为城市化从三个方面影响河流生态系统结构,一是河流面积,二是河流的河床结构,三是景观尺度上的空间结构;城市化从水文过程和物质循环过程引起河流生态功能变化。河流恢复的难点在于河流系统的复杂化,因此基于不同区域的多目标管理是河流管理和恢复的方向。  相似文献   

20.
Dynamic aperture control technology is one of the most important parts in ultrasonic imaging system. Excellent control technology of dynamic aperture can effectively improve the quality of ultrasonic imaging. Based on deep analysis of ultrasonic beam distribution, a control method for dynamic aperture which can eliminate the scanning dead zone of focused beam is presented. The detection region is even divided according to the number of probe array elements. The desired focused beam width is calculated between the next two scan lines at different depths, and then according to the beam width, the required aperture size for different depths is determined. The method is not affected by the probe parameters or detection objects, and it can be widely employed in ultrasonic imaging system. The simulation experiments indicate that the proposed method can effectively improve the whole quality of ultrasonic imaging.  相似文献   

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