一种微处理器控制的膜厚测量仪器

本文介绍了一种电脑膜厚测量仪器的工作原理及其结构，讨论了实现膜层厚度非线性的校正方法

一种无线温度检测系统的设计

本文采用dS18b20温度传感芯片与MSP430f1121A单片机实现环境温度的检测,通过nrf2401芯片完成数据的无线传输,在接收方利用AT89C2051的串口与计算机交换数据,实现计算机的远距离无线温度检测,该系统简单实用,性价比好

基于C51与CAN总线的汽车电子控制系统单元设计

本文在分析汽车总线技术应用的基础上,介绍了基于CAN总线的汽车电子控制系统单元的设计与实现。给出了控制模块、CAN通信模块的硬件设计及软件分析,并给出了基于C51的实例

A Floater Liquidometer Using Hall Effect

本文介绍了一种新型液位计，它根据霍尔效应，选用了霍尔开关矩阵作为敏感元件，利用磁浮子进行液位指示，满足了在高压密封环境下测量液位的要求。The paper is an introduction to a new floater liquidometer which use hall effect. This liquidometer has hall matrix as sensor, uses magnetofloater to indicate liquid level and fufills the measure of high pressure and hermetic circumstance

Channel analysis and precaution of interferences in CAN-BUS

本文通过对CAN总线特性和总线信道的分析,利用汽车CAN电子控制系统的实际情况探究了汽车CAN总线的干扰问题,并且提出了实践证明可行的防干扰措施;同时探讨了CAN总线传输信息的速率、信道容量和节点容量等技术问题。In this paper, we analyzed the characteristic and signal channel of CAN-BUS, researched into interferenced problem, and advanced many measures against interference which were testified in a car system of CAN-BUS. And we discussed the CAN-BUS key technical such as the transmission speed, channel capacity, node capacity, and so on

Using Feedback Servo Mechanism to Scale-up the Measurement Range on the Shift by Hore Sensor

霍尔器件可用于微位移测量 ,但通常只能测 1mm左右的位移 ,并在实用时要设计复杂的磁路以保证在测量范围内梯度磁场为均匀的。本文采用反馈随动机构带动霍尔传感器跟踪被测体的位移 ,从而扩大了测量范围 ,且不需要在测量中保持均匀梯度磁场Hore part may be used in measuring tiny shift,but in practice,a complicated magnetic circuit should be designed to assure the uniform gradient magnetic field in the measurement range,which is usually within 1mm.In this paper,a feedback servo mechanism is used to make the Hore sensor tracking the shift of the measured object.In this way the measurement range of shift is extended greatly.And the uniform gradient magnetic field during measurement is not demanded.福建省自然科学基金资助项

Design of distributed PLC based on logical analysis

传统PlC成本较高并有其技术专有性,在一些要求成本低和操作简便的工业控制场合很难满足要求。以工控领域的一些低成本、分布式、易操作应用场合的需求为基础,研究一种基于逻辑分析的分布式PlC实现方案。通过对系统数学模型的分析,采用逻辑表达式解析算法实现了PlC的可编程逻辑功能;采用CAn总线拓展了网络功能,实现分布式结构;采用向导式界面,增强其易操作性;通过强化软件功能,裁剪硬件,降低成本。The traditional PLC has high cost and its proprietary technology,it can not meet the requirements in some industrial control applications which requires low cost and easy to operate.To meet the using needs in some low-cost,distributed and easy to operated industrial areas,this paper tries to explore the distributed PLC based on logical analysis.Through the analysis of the mathematical model of the system,the system has achieved the PLC programmable logic functions by using a logical expression analysis algorithm,and expanded the network function by using CAN bus.It also enhances its operability by using the wizard-style interface,and cuts the costs through enhancing software and cutting hardware

The Novel Control Strategy Research on Resonant Bridge Modular Switched-Capacitor Converter

在提出的一款谐振型桥式模块化多电平开关电容变换器拓扑基础上,提出了移相加PWM的控制策略。该控制策略实现了变换器高频开关(MOSFET)的零电流、零电压开关,并在保证变换器较高效率运行的基础上,实现了变换器输出电压的可调性,解决了回路峰值电流过大或过小的问题。详细分析了开关电容变换器高频开关移相角与输出电压和回路峰值电流之间的关系,并通过仿真软件SABER和硬件平台对所述控制策略下的软开关、输出电压、峰值电流特性进行了验证,仿真结果与实验结果均证实了上述结论。This paper presents a phase shift plus PWM control strategy for the novel resonant bridge modular multilevel switched-capacitor converter. The proposed method ensures that almost all switching devices keep zero current switching or zero voltage switching, which achieves a high system efficiency. Meanwhile, the output voltage is regulated and the loop peak current is limited in a proper range. The impacts of the switching phase of metal-oxide-semiconductor field-effect transistors( MOSFETs) on both the output voltage and the loop peak current are deduced,respectively. By means of simulation software Saber and hardware platform,the proposed characteristics of soft switching,output voltage,and peak current are verified well.国家自然科学基金(61671400);; 中央高校基本科研业务费(20720150088);; 广东省自然科学基金(2016A030313657);; 福建省科技计划项目(2014H6026);; 福建省自然科学基金(2015J201274)资

Electrical conductivity measurement using frequency self-adaptation current source to surmount the influence of capacitance

在电导率的测量中,为减小极化作用的影响,交流电源的频率越高越好,但频率提高的同时电容作用的影响也随之增强,因此,选择合适的频率是提高测量精度的关键。本文提出了一种在电导率测量中如何选择合适的信号测量源工作频率的方法,在恒流源驱动下,判断电导池输出电压导数可自动确定信号测量源工作频率。本文从理论上对该方法进行了分析,并给出实现的硬件电路和实验结果。In conductance measurement process, high signal frequency can decrease the error generated by polarization, but it can also increase the error caused by cable capacitance at the same time. So, it is a key point to choose a suitable frequency to improve the measurement accuracy. This paper introduces a method for choosing a suitable working frequency of the measurement signal source. Driven by a constant current source, the output voltage derivative of conductance pool can be estimated and the working frequency of the measurement signal source can be determined automatically. This paper not only analyses the method theoretically but also provides the practical circuit and experiment results

The Impact of Complex Cumulants'conpling Properties on the Results of Fault Diagnosis

复数三阶累积量具有不同的定义形式,定义形式不同,其包含的耦合信息也不相同。在复数累积量切片以及三阶对角累积量的基础上,定义了三阶累积量切片谱以及三阶对角累积量谱,实验中利用这两种谱的不同的耦合方式,通过计算容量维,对采集的故障信号和正常信号进行故障判别。实验结果表明,两种定义方式的谱,在不同的耦合方式下,对同一故障的诊断正确率结果类似,表明了影响故障诊断结果的不是谱的形式,而是其中包含的不同的耦合信息。Complex third-order cumulant has different definition forms.Different forms conclude different information.Based on three order cumulant slices and diagonal cumulants,complex third-order cumulgant slices spectrum and diagonal cumulant spectrum are defined.In experiments,using the different coupling modes,the capacity dimensions are caculated to diagnose faults.Experiments indicate,the two kinds of spectrum in different modes,the detection accuracy rates on the same fault are similar,thus,the experiments proved that the diagnosis result is not effected by different kinds of spectrum forms,but by the different coupling information included in the spectrum.国家自然科学基金资助项目(50975098); 厦门市科技计划资助项目(3502Z20123013