基于声波分析的臭氧发生器电源谐振频率测量仪

由于当前臭氧发生器高频电源谐振频率检测方法具有昂贵、危险等缺点,设计一种基于声波频谱分析的高频电源谐振频率检测仪器。通过分析臭氧发生器工作环境下的声波数据与高频电源谐振状态的关系,找到测量谐振频率的方法。该仪器使用STM32单片机作为核心控制及计算单元,通过声波采集电路将声波数据传送给单片机,单片机基于声波数据使用频谱分析程序测量出谐振频率。实践分析结果表明,基于声波分析的臭氧发生器电源谐振频率测量仪具有高效、安全、经济等优点。     

基于多条耦合器的双声路声表面波气体传感器

针对目前声表面波气体传感器在消除外界因素干扰及抑制体声波中存在的问题,提出一种基于多条耦合器的双声路声表面波气体传感器结构.由于该传感器中的双声路结构关于输入小波换能器左右对称,且具有相同的设计参数,所以该传感器可以消除由于外界测量条件改变而引起的扰动量.同时,由于将具有体声波抑制功能的多条耦合器应用到传感器中,所以能够对造成假响应信号的体声波进行有效地抑制.此外,该传感器中的输入换能器采用了小波函数包络进行加权,所以与传统等指长、等周期的均匀换能器相比提高了对频率响应曲线中旁瓣的抑制效果.中心频率为101.764 MHz SO2气体传感器的实现和测量结果表明,该气体传感器在测量范围内,对各种浓度的SO2气体具有好的响应特性:传感器在0.5×10-6到20×10-6浓度范围内,SO2气体浓度与输出频率参量信号之间具有比较理想的线性特性,测量的灵敏度约为6.5 kHz/10-6.     

DDS在信号发生器中的应用

提出了以AVR单片机中的ATmega8为主控芯片,利用直接数字频率合成法（DDS）的原理,从“相位”的概念出发进行频率合成。这种方法不仅可以给出不同频率的正弦波,而且还可以给出不同初始相位的正弦波,甚至可以给出各种任意波形。     

基于ATmega16单片机的无线遥控地板清洁机设计

设计了一种基于ATmega16单片机的智能地板清洁系统,介绍了清洁机的总体设计,各组成部分原理和功能及系统的软件设计。利用加速度传感器产生信号作为控制信号的主要来源,采用无线信号的接收和发送模块,使遥控部分与主机器部分联系起来,最后通过ATmega16单片机控制两个直流电动机,实现清洁机在各个方向的运动。     

一种快速检测粮食水分的数据处理方法研究

提出一种快速检测粮食水分的数据处理方法,给出了利用单片机定时／计数器求脉冲信号频率的算法程序,搭建了频率和粮食水分的教学模型,设计了利用RS-485的数据通信方案.系统采用ATmega128单片机为处理器,以满足处理大量数据的需求.实际应用结果验证了这种数据处理方法,具有较好的测量准确性和稳定性.     

低成本两相步进正弦细分驱动器的设计

本文介绍了一款以AVR ATmega单片机为控制核心,利用软件产生正弦波信号和步进脉冲时序,以相电流与设定值的差值调节脉冲相电压为工作原理的两相步进正弦细分驱动器的设计方法.该系统运行以来,稳定可靠,达到了设计要求.     

基于双处理器和CAN总线的现场液位智能控制器

利用AVR 8位高速单片机ATmega64和ATmega162以及具有国际标准的CAN总线,采用双处理器、双口RAM IDT7130数据缓存的结构,设计了一个用于工业现场液位控制调节的智能控制器.在重点设计控制器硬件结构电路和软件流程的同时,尝试应用了多种液位控制算法.不仅可以实现工业现场液位对象的智能监测、控制和调节,而且可以有效地提高工业现场液位对象的计量精度和自动化水平.     

基于ATmega16单片机的甲烷浓度控制系统设计

文章设计了一种基于ATmega16单片机的甲烷浓度控制系统,ATmega16单片机是AVR单片机中的高档ATmega系列,具有增强型RISC内核的Flash的单片机,且具有高速处理能力。文章介绍了甲烷浓度控制系统的组成和工作原理,并给出了系统的硬件电路设计和软件设计。     

基于AVR单片机的3D打印机喷头PID算法温控系统设计

设计一种基于ATmega128a单片机的3D打印机温度控制系统,该系统采用AVR单片机作为控制单元,Max6675模块进行温度采集,并且通过数码管显示温度数值,进行PID运算并控制IRF540输出的PWM的占空比,完成对喷头温度的调节。     

红外线光电开关在输送带速度测试系统中的应用

提出一种基于ATmega8单片机和计算机控制的带式输送机带速测试系统,它可以完成胶带速度的测试、实时监控和速度曲线的绘制。系统包括计算机和单片机,两者之间采用RS232进行数据通信。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.