Dynamic compensation for sensors based on particle swarm optimization and realization on LabVIEW

以冲击波压力测试为背景,介绍了一种基于粒子群优化算法(PSO)的动态补偿数字滤波器的设计方法。对压力传感器进行动态校准实验和计算机仿真,根据传感器动态标定时的输入输出数据及参考模型,利用粒子群优化算法进行寻优,得到的全局最优值即为传感器动态补偿器的系数,并利用LabVIEW平台完成了动态补偿滤波器的设计。实验结果表明:经过补偿器处理后的信号与输入的被测信号有良好的一致性。     

Study on compound ultra-precision alignment technique

A nano-displacement measurement system with duo-gratings is analyzed by using optics theory,a mathematic model for the system is established,and the characteristic of laser Moirésignals is studied through CAD simulation.To improve signal sensitivity and positioning accuracy,two methods of precision positioning are brought forward：differential Moirépositioning method and modified Moirépositioning method.A compound control system for precision positioning is set up by combining these 2 Moiréalignment methods,in which the modified Moiréalignment technique is used for coarse alignment and the differential Moiréalignment technique is used for fine alignment,and the system obtains positioning accuracy of±10 nm in±500μm positioning range with shot response time.     

An alternative illumination source based on LEDs for PIV measurements on human swimmers—A feasibility study

Methods for flow visualization help to investigate the motion of fluids that are normally invisible. Especially, Particle Image Velocimetry (PIV) – with a laser as light source – has been established in the field of engineering and partly in biology. Since the standard measuring equipment applying a laser system is very sensitive with respect to transport, temperature, humidity as well as laser safety requirements have to be adhered, the observation and classification of flow pattern around human swimmers in swimming pools has been rarely applied. There is a need for a simple, powerful, affordable, robust, and portable illumination source which shall not harm the swimmer by exceeding the permitted maximum radiation for human skin and eyes. As a result, this technical note demonstrates an alternative light source system based on LEDs which enables PIV measurements around human swimmers similar to experiments with a (traditional) laser system. As an example, the flow fields of two different swimmers with a similar movement and phase are compared using both illumination methods laser and LED. Furthermore, a series of sequential velocity fields, produced by the motion of a monofin swimmer, generate a vortex pair with an inverse Karman vortex street which is typically seen in fish and marine mammal locomotion. Consequently, this LED illumination source is show to provide a sufficient suitable light intensity as well as light quality enabling the measurement of the flow field around swimmers.     

Research on Reaction-bonded SiC for Optical Application

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Study on the Effect of Track Curve Radius on Friction-Induced Oscillation of a Wheelset–Track System

Abstract

The purpose of this article is to investigate the correlation between the friction-induced oscillation of a wheelset–track system and curve radius and to explain a general phenomenon of rail corrugation based on the viewpoint of friction-induced oscillation. The typical phenomenon of rail corrugation in metros is that corrugation generally arises when the curve radius is quite small, whereas it rarely occurs when the curve radius is larger or on a straight track. Different multibody models of the vehicle–track system and finite-element models of the multiple-wheelset–track system with different curve radii are established, respectively. According to the creep force analyses and unstable vibration analyses, the correlation between the creep force and friction-induced oscillation can be identified. Then the effect of the track curve radius on the friction-induced oscillation of the wheelset–track system can be summarized, which provides an explanation of the typical phenomenon of corrugation.     

A note on “Single-machine scheduling problems with release time of jobs depending on resource allocated”

A result in a recent paper reported by Zhang et al. (Int J Adv Manuf Technol 57:1175–1181) is incorrect because job processing times are variable due to both deteriorating jobs and learning effects, which is not taken into account by the authors. In this note, we show by a counter-example that the published result is incorrect and provide the corrected result.     

Development of Sulfide‐Selective Optode Membranes Based on Immobilization of Methylene Blue on Optically Transparent Triacetylcellulose Film

Abstract

The development of reversible sulfide‐selective optode membranes, based on immobilization of methylene blue (MB) on optically transparent triacetylcellulose film, is described. The sensing scheme of the sulfide‐selective optode membranes is based on the decreasing absorbance of the membrane at 654 nm in the presence of sulfide, which can be related to the sulfide concentration in solution. The dynamic working range, detection limit, sensitivity, selectivity, and effect of pH are discussed in detail.

Under optimum experimental conditions, the membrane system shows a calibration response range from 3.1×10^?5 to 6.1×10^?4 M in a phosphate buffer of pH 7.5. Typical response times in the samples are 15–20 min. The lifetime of the system was about 30 days, with a relative standard deviation of <2%. The sensing membrane showed a good selectivity to sulfide over other anions. The optode membrane was applied to the determination of sulfide in real samples.     

Methodology for evaluating effects of material characteristics on machinability—theory and statistics-based modelling applied on Alloy 718

The potential machinability for Alloy 718 (Inconel 718) is examined in terms of five material characteristics considered to play a key role in the machinability: ductility (elongation to fracture), strain hardening (ultimate tensile strength over yield strength), thermal conductivity, yield strength and abrasiveness (amount of carbides). The material characteristics are simulated with the software JMatPro from Sente software. The effects of composition, grain size, hardness (size of the precipitated intermetallic particles for given volume fraction), heat treatment, temperature and strain rate have been modelled and statistically evaluated. Combining thermodynamics-based modelling (JMatPro), design of experiments and statistical analysis (Minitab), and machinability polar diagram, a concept on methodology to assess variations in material specifications and to optimise these specifications with respect to potential machinability has been developed. The mechanical properties, predicted from the meta-modelling are found to be affected by the same parameters: hardness (intermetallic particles characteristics), grain size, amount of aluminium, strain rate and temperature. The abrasiveness should only be affected by the amount of carbon. Simulated material characteristics for two different types of turbine discs were compared with measured tool wear from production environment machining experiments. Variations in material characteristics between the discs were small as well as the critical tool wear, revealing a robust metal cutting process.     

Study on Influence of Cylinder Liner Surface Texture on Lubrication Performance for Cylinder Liner–Piston Ring Components

A marine diesel engine, where the cylinder liner–piston ring (CLPR) pair is one of the most important rubbing pairs, is the heart of a marine system. Studying the lubrication characteristics of the CLPR will provide a guide for rational design of the CLPR to reduce wear and prolong its service life. The surface texture features have a significant impact on the lubricating performance of the CLPR. In this study, the tribological system of the CLPR was investigated. Different surface textures (such as different sizes of surface concaves and grooves, etc.) were designed and produced on the cylinder liners using surface treatment. A series of experimental tests were then carried out in a specially designed diesel engine tester to investigate the tribological characteristics of the treated CLPR pairs. The comparison analyses of the worn surface texture features, element content of the lubrication oil, and abrasive particle characteristics were conducted under different wear surface texture features and cylinder liner speeds. The analysis results showed that there were significant differences in the tribological and lubrication properties of the rubbing pairs in different wear surface texture features. The wear performance of the CLPR pair with a regular concave texture was superior to that of the concave and groove, and regular groove textures. In addition, the regular concave with a depth-diameter ratio of 0.1 was the most effective surface texture to improve the lubrication and wear properties of the CLPR pairs. It is believed that the knowledge obtained in this study provides the real practical basis for tribological design and manufacturing of CLPR pair in marine diesel engines.     

Chinese Plastic Machinery Industry Takes on Fast Development

According to the statistics of Chinese Plastic Machinery Industry Association, the sale income of plastic processing equipment in China amounts to 21.205 billion Yuan in 2006, the same ratio grows 20.47%.[第一段]     

Discussion on Temperature Profile in End-pumped Laser Rods

在分析了端面泵浦、周边冷却的固体激光棒内生热及致冷机制的基础上，将轴对称系统内的热传导问题简化为仅考虑径向热流的一维方程，并推导出“大礼帽”型光束泵浦及高斯光束泵浦两种情况下激光棒内温度分布的表达式。结果表明，在同样的光束尺寸下，利用高斯光束泵浦将导致棒内更加剧烈和更加不均匀的温度变化。文中对讨论进行了无因次处理，以使所获得的结论能够适用于不同的激光材料。     

Time partitioning based on the job-flow schedule — A new approach to optimum allocation of jobs on machine tools

A time-partitioning scheme with constant job-mix divisions (stages) is presented. The scheme is the basis for using a combination of linear programming and heuristic to solve the dynamic optimisation problem of job allocation through an algorithm which also incorporates the set-up times. The algorithm uses a pull logistic towards the due dates. The results of a case study of a single operation job-shop, indicate increased utilisation of machine tools, reduced work-in-process inventory and additional free capacity owing to reduced makespan of jobs. Application of the algorithm can be extended to multiple-operation job shops, which are common in industrial practice.     

Prevention of undesired vibrations on t est benches

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Game “Divi-Divi-Dip” Based on Interactive Robot

Recently the improved robot working in very various fields,many researchers are trying to develop the robot to help people in the service field.However people who meet a robot in the first time generally get heterogeneous feeling.To resolve this,we suggest an interactive game with robots to increase the friendliness.The game,called "Divi-Divi-Dip" with 3 different body poses,is first introduced in a Korean TV program.The robot is using the visionary technology to recognize the pose with camera for the interactive game.     

Study on hardware-in-the-loop simulation of beer fermentation system

啤酒发酵过程是一个复杂的生化反应过程,控制目标是控制发酵罐内麦汁的温度符合发酵温度曲线,保证发酵的顺利完成。针对控制对象大惯性、大时滞及3个温区相互耦合的特点,我们采用数字增量式PID控制算法实现控制,控制量经过对角阵解耦后作用到控制对象。最后,啤酒发酵系统由VB程序和组态王软件仿真。该系统可以在实验室中完成的,具有安全性高、成本低的特点,非常适用于实验教学。     

Fuze battery test system based on negative delay

本文研究了一种定容量循环存储方法来实现对引信电池工作时电压及噪声的监控。针对有限的存储空间,采用负延迟触发的方法对每片Flash设计了4 MB的循环采样空间来记录触发前4 MB的数据,并实现触发后顺序记录50 MB的数据;采用两片Flash交替工作的方式,避免了命令传送与数据编程在时间上的冲突。该方法合理地利用了存储空间,有效地记录触发前的信息,保证了数据的可靠性和正确性。实验测试表明:该系统可实现对引信电池的监测。     

Mine-used multi-function serial signal converter based on Ethernet

介绍了一种以STM32互连型系列微控制器STM32F107VCT6为核心的矿用多功能以太网串口信号转换器。该转换器移植了μC/OS-II嵌入式操作系统,并嵌入了LwIP协议栈,通过软硬件的设计实现了以太网信号与M-Bus信号、RS485信号与RS232信号的相互转换,使煤矿井下各种监控设备接口之间的互联更加便捷。该转换器有效解决了各种监控系统和通信系统之间的兼容性问题,提高了安全监控系统的整体性能,具有很好的应用价值,值得在煤矿安全生产中推广使用。     

Study on the vehicle license plate tilt correction

The shortage of current different approaches of the vehicle license plate(VLP) tilt correction is analyzed in the paper and a new rotary correction method put forward based on the former ways of the VLP tilt correction in the horizontal direction and the vertical direction Owing to the VLP tilt taking place in the vertical direction, the array of the image's pixels of the same column is broken, and even different rows come into being superposition.The VLP tilt taking place in the horizontal direction, by which the array of the image's pixels of the same row broken, and so much as different columns come into being superposition.     

Influence of Cage Clearance on Bearing Lubrication©

The effect of the cage clearance on the lubricant supply and elastohydrodynamic (EHL) film thickness has been studied in a ball-on-disc device. A single pocket from a standard nylon cage was mounted around the ball. The cage was instrumented so that the clearance between the cage and ball could be altered. Film thickness measurements were made with and without the cage present and for different clearances. Two lubricants were tested: a lithium hydroxystearate grease and its base oil. Film thickness was measured with increasing speed to determine the onset of lubricant starvation. Without a cage present the grease lubricated contact starved at a very low speed, typically 0.02 m/s and the film thickness dropped to a fraction of the fully flooded value. Starvation did not occur within the speed range for the base oil.

The presence of the cage significantly changed the starvation response. For the base oil reducing the clearance induced starvation by locally removing the lubricant from the track. The grease gave a very different result as reducing cage clearance increased the starvation speed thus ensuring fully flooded behavior over a much greater speed range. The improvement in grease performance with the cage present is attributed to two effects. First, the cage with reduced clearance helps to redistribute the grease into the track. Second, the close conformity between cage and ball promotes shear degradation of the grease structure generating low-viscosity material, which improves replenishment.