抗干扰的

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

The collector in dynatron of smooth Ou photosensitive or blast off extremely direct receive laden resistor to be able to satisfy lesser laden requirement; to be in of dynatron of smooth Ou photosensitive blast off extremely add dynatron enlarge drive, the push-pull type circuit that through two photoelectricity coupler makes and feedbacking through increasing photosensitive dynatron base, reach stronger laden capacity already, increased the interference rejection capacity of power interface, the outputs power inadequacy weakness that overcame smooth Ou, raise the switch rate of smooth Ou again, overcame the distributinging capacitance as a result of existence of smooth Ou oneself, cause an effect to transmitting speed.

在光耦光敏三极管的集电极或发射极直接接负载电阻即可满足较小的负载要求；在光耦光敏三极管的发射极加三极管放大驱动，通过两只光电耦合器构成的推挽式电路以及通过增加光敏三极管基极正反馈，既达到较强的负载能力，提高了功率接口的抗干扰能力，克服了光耦的输出功率不足的缺点，又提高光耦的开关速度，克服了由于光耦自身存在的分布电容，对传输速度造成影响。

The research work of this paper is divided into five parts: The first ,according to the work characteristics of ship's auxiliary boiler, this paper is to design applied project in the automatic control system of ship's auxiliary boiler; The second, according to the work request of the cargo winch of alternating three-speed change-pole speed-adjusting, this paper is to determine adopting the method of the PLC control; The third, this paper is to design PLC application in three -phase induction motor control, to give the ladder chart, program and input and output circuit diagram; The fourth, this paper is to research the method of the ship's combined starting screen automatic control with the PLC; The fifth, this paper is to inquire the possibility of apply the PLC in ship's engine room surveillance system; According to the comprehensive analysis of above actual example of ship's auxiliary machinery automatic system with the technique of PLC; not only can use the technique of PLC to replace traditional relay-contactor control technique in ship's auxiliary machinery automatic system, but also can get the conclusion of the former is more dependable and more clever than the latter, the maintenance is more convenient, thus develop a new path for ship automation.

本文研究的工作主要包括五个部分：第一，根据船舶辅锅炉的工作特点，设计PLC在船舶辅锅炉自动控制系统中的应用方案，主要有PLC选型及输入输出点的设计，画出系统控制梯形图并分析工作原理；第二，根据交流三速变极调速起货机的工作要求，确定采用PLC控制的方法，进行控制系统的硬件设计和软件设计，并分析工作原理：第三，设计了PLC在三相异步电动机控制中的应用，给出了控制梯形图、程序及输入、输出接线图；第四，研究了用PLC实现船舶组合起动屏自动控制的方法，进行了系统的电源设计和软件设计，给出系统工作流程图；第五，探讨了船舶机舱监视系统应用PLC的可行性，将继电器报警线路改为用PLC控制报警，给出系统硬件图和软件梯形图，并分析了PLC机的选型、抗干扰和应用PLC的经济效益和社会效益等问题。综合以上船舶辅助机械自动控制系统采用PLC技术的实例分析，可以得出船舶辅助机械自动控制系统不但可以使用PLC技术取代传统的继电器接触器控制技术，而且前者比后者更可靠、更小巧，维护保养更方便的结论，从而为船舶自动化开辟了一条新的路径。无忧毕业设计网 www.5ubs.cn

We have developed many kinds of optical methods to measure the insect flight. For example, a beating force measurement method reduces the uncertainty caused by air turbulence; a flow measurement using a frame straddling technique decreases the interval between exposures of the flow;extracting the weak distorted fringes on the dragonfly wing by a correlation algorithm; measuring the camber deformation of a dragonfly wing using projected comb fringe without hypothesizing that the wing is a rigid plate. By measuring the beating force, wing kinematics and flow, simutantously, we can analyze the relationship among many flight parameters.

本研究针对昆虫运动的特点，研究开发了测量昆虫运动，特别是自由飞行昆虫运动的光学方法，包括：风洞中扇翅力的测量，解决高灵敏度光学测量的抗干扰问题；帧头帧尾流场测量方法，解决由CCD拍摄帧频导致的测量速度低的问题；调制相关算法，解决透明翅膀上散射光较弱问题；梳状条纹投影法，解决翅膀弓形变形测量问题，不需要以往的翅膀刚性平板或刚性条杆假设；多参数的综合测量，解决各参数间的相位匹配问题。

The experiment shows that the recognizing rate reaches 99% and the recognizing time of 16 digitals is less than 0.5ms.The method is much more applicable for the requirements of the recognition speed and accuracy of digital meters and this method is robust.So it has very high value for application.

实验表明，数字仪表显示值的快速识别方法的识别率达99％，对16位数字的识别时间不超过0.5毫秒，并具有较强的抗干扰能力，完全满足仪表显示值实时自动识别对准确率和速度的要求，具有较高的应用价值。

A nonlinear adaptive speed controller based on adaptive backstepping approach for permanent magnet synchronous motors with nonlinear coupling and parameter uncertainties is presented. With the preposed controller, the parameter uncertainties are compensated and high performance speed controller for permanent magnet synchronous motors is shown to be globally asymptotically stable. The scheme is robust to the parameter uncertainties and load torque disturbance.

针对永磁同步电动机系统的非线性耦合特性以及参数的不确定性，采用自适应反步控制实现永磁同步电动机的非线性控制，在补偿参数不确定性影响，提高系统的抗干扰能力的同时，实现了永磁同步电动机的高性能全局渐近稳定速度跟踪控制。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。