Fast filtering algorithm based on vibration systems and neural information exchange and its application to micro motion robot

This paper develops a fast filtering algorithm based on vibration systems theory and neural information exchange approach. The characters, including the derivation process and parameter analysis, are discussed and the feasibility and the effectiveness are testified by the filtering performance compared with various filtering methods, such as the fast wavelet transform algorithm, the particle filtering method and our previously developed single degree of freedom vibration system filtering algorithm, according to simulation and practical approaches. Meanwhile, the comparisons indicate that a significant advantage of the proposed fast filtering algorithm is its extremely fast filtering speed with good filtering perfi^rmance. Further, the developed fast filtering algorithm is applied to the navigation and positioning system of the micro motion robot, which is a high real-time requirement for the signals preprocessing. Then, the preprocessing data is used to estimate the heading angle error and the attitude angle error of the micro motion robot. The estimation experiments illustrate the high practicality of the proposed fast filtering algorithm.

Investigation on the Radial Micro-motion about Piston of Axial Piston Pump

The limit working parameters and service life of axial piston pump are determined by the carrying ability and lubrication characteristic of its key friction pairs. Therefore, the design and optimization of the key friction pairs are always a key and difficult problem in the research on axial piston pump. In the traditional research on piston/cylinder pair, the assembly relationship of piston and cylinder bore is simplified into ideal cylindrical pair, which can not be used to analyze the influences of radial micro-motion of piston on the distribution characteristics of oil-film thickness and pressure in details. In this paper, based on the lubrication theory of the oil film, a numerical simulation model is built, taking the influences of roughness, elastic deformation of piston and pressure-viscosity effect into consideration. With the simulation model, the dynamic characteristics of the radial micro-motion and pressure distribution are analyzed, and the relationships between radial micro-motion and carrying ability, lubrication condition, and abrasion are discussed. Furthermore, a model pump for pressure distribution measurement of oil film between piston and cylinder bore is designed. The comparison of simulation and experimental results of pressure distribution shows that the simulation model has high accuracy. The experiment and simulation results demonstrate that the pressure distribution has peak values that are much higher than the boundary pressure in the piston chamber due to the radial micro-motion, and the abrasion of piston takes place mainly on the hand close to piston ball. In addition, improvement of manufacturing roundness and straightness of piston and cylinder bore is helpful to improve the carrying ability of piston/cylinder pair. The proposed research provides references for designing piston/cylinder pair, and helps to prolong the service life of axial piston pump.

Micro-motion dynamics analysis of ballistic targets based on infrared detection

The dynamic characteristics related to micro-motions, such as mechanical vibration or rotation, play an essential role in classifying and recognizing ballistic targets in the midcourse, and recent researches explore ways of extracting the micro-motion features from radar signals of ballistic targets. In this paper, we focus on how to investigate the micro-motion dynamic characteristics of the ballistic targets from the signals based on infrared (IR) detection, which is mainly achieved by analyzing the periodic fluctuation characteristics of the target IR irradiance intensity signatures. Simulation experiments demonstrate that the periodic characteristics of IR signatures can be used to distinguish different micro motion types and estimate related parameters. Consequently, this is possible to determine the micro-motion dynamics of ballistic targets based on IR detection.

High-Precision Wideband Phase-Derived Velocity Measurement for Micro-Motion Extraction

A phase-derived velocity measurement method is proposed in a wideband coherent system,based on a precise echo model considering the inner pulse Doppler effect caused by fast moving targets.The Cramer-Rao low band of velocity measurement precision is deduced,demonstrating the high precision of the proposed method.Simulations and out-field experiments further validate the effectiveness of the proposed method in high-precision measurement and micro-motion extraction for targets with weak reflection intensity.Compared with the long-time integration approaches for velocity measurement,the phase-derived method is easy to implement and meets the requirement for high data rate,which makes it suitable for micro-motion feature extraction in wideband systems.

A Pipeline Inspection Micro Robot Based on Screw Motion Wheels

The micro robot based on screw motion wheels, which features high payload/mass ratio, fast and continuous motion, adaptation to pipe diameter or roundness variations, is suitable for locomotion and inspection inside small diameter pipelines. The robot inspection system, Tubot I, developed at Shanghai University is composed of locomotion mechanism with an inner motor, a micro CCD camera and a monitor outside the pipeline. In the paper, the kinematics and statics analyses are presented for the screw locomotion system of Tubot I. The moving characteristics are obtained from experiments on the robot prototype.

Micro-Scale Motion Precision Simulation Method for a New-Type 6-DOF Micro-Manipulation Robot

A new 6-DOF micro-manipulation robot based on 3-PPTTRS parallel mechanisms in combination with flexure hinges is proposed. The design principle of the mechanism is introduced, and the kinematics analysis method based on differentiation is used to get the (inverse) kinematics equations. Then a micro-scale motion precision simulation method is proposed according to finite element analysis (FEA), and the prediction of robot’s motion precision in design phase is realized. The simulation result indicates that the 6-DOF micro-manipulation robot can meet the design specification.

基于Micro-PIV的微观流场检测技术

介绍了一种针对微观流场检测数字粒子图像测速技术,通过添加荧光显微装置,改进激光入射与照明方式、聚焦平面控制以及纳米级示踪粒子布朗运动误差消除算法等软硬件方面的技术创新,解决了微观检测的关键问题。针对微流体特征尺度小、精度要求高的特点,建立了具有自主知识产权的Micro-PIV微流场测试平台,并就几种典型微观流场进行了检测。试验结果表明该测试技术可对微米级稳态、瞬变流场进行全流场速度分布的检测,各项性能指标达到国际先进水平。

Micro-PIV技术-粒子图像测速技术的新进展

Micro-PIV是近年来发展起来的一种微尺度流动测速技术.它是传统PIV测量与光学显微技术相结合的一种整场、瞬态、定量测量方法,其基本测速原理与传统PIV相同,但在示踪粒子选择、图像获取和处理等方面两者存在较大差别.Micro-PIV突破了传统微尺度流体力学测量手段的局限性,使得对微尺度流动元件的研究从过去只能给出流量、阻力特性等有限信息逐步转向对全流场内流结构的直接测量上,并且达到了相当高的分辨率和测量精度.本文对近几年Micro-PIV技术发展状况进行了总结和分析,论述了Micro-PIV技术与传统PIV的主要区别以及具体的处理技术,反映了其在科学与工程中的应用,并对此项技术的发展作了展望.

Mini/Micro LED巨量转移技术研究与发展现状

对巨量转移(Mass Transfer, MT)方案和运动定位平台(Motion Positioning Platform, MPP)的研究现状及其未来发展进行了详细阐述。根据芯片转移方式,将MT方案分为精准拾取-释放技术、自组装技术、滚轴转印技术、激光剥离技术,结合芯片转移效率和良率,论述了国内外MT方案的发展过程。在此基础上,从平台支撑方式,详细介绍了机械构型、气浮构型、磁浮构型和混合构型的MPP结构及工作原理,考虑运动行程、运动定位精度等因素,比较了MPP性能的优劣。展望了MT方案和MPP技术的未来发展方向,指出基于微孔液气双态介质的激光剥离MT和具备周向小角度修正以及轴向微高度调节能力的“机械+磁浮”混合构型MPP是Mini/Micro LED芯片转移技术的研究重点。

Modeling simulation and experiment of micro-Doppler signature of precession

Spatial precession is a special micro-motion of the spinning-directional target, and the micro-Doppler signature of the cone-shaped target with precession is studied. The micro-motion model of precession is built first, and then the micro-Doppler model is developed based on the proposed concept of micro-motion ma- trix, by which the theoretical formula of micro-Doppler signature of precession is derived. In order to further approach to the actual case, the occlusion effect is firstly considered in micro-Doppler, and the simulated result with occlusion effect is well in accordance with the measured result in microwave anechoic chamber, which suggests that the micro-motion model and micro-Doppler model of precession are both valid.

Effects of site conditions on earthquake ground motion and their applications in seismic design in loess region

The Loess Plateau is an earthquake prone region of China, where the effects of loess deposit on ground motion were discovered during the 2008 Wenchuan earthquake(Ms8.0) and the 2013 Minxian-Zhangxian earthquake(Ms6.6). The field investigations, observations, and analyses indicated that large number of casualties and tremendous economic losses were caused not only by collapse and damage of houses with poor seismic performance, landslides, but also amplification effects of site conditions, topography and thickness of loess deposit, on ground motion. In this paper, we chose Dazhai Village and Majiagou Village as the typical loess site affected by the two earthquakes for intensity evaluation, borehole exploration, temporary strong motion array, micro tremor survey, and numerical analysis. The aim is to explore the relations between amplification factors and site conditions in terms of topography and thickness of loess deposit. We also developed site amplification factors of ground motion for engineering design consideration at loess sites. The results showed that the amplification effects are more predominant with increase in thickness of loess deposit and slope height. The amplification mayincrease seismic intensity by 1 degree, PGA and predominant period by 2 times, respectively.

人群疏散模拟仿真软件系统自主研发与应用——以Pedynamics为例

为更加精准地分析与评估公共场所突发事件下人员疏散的需求,自主研发了新一代人群疏散模拟仿真软件Pedynamics。以某地铁场景为例,比较分析Pedynamics与商业软件Pathfinder和AnyLgoic用于模拟地铁车站不同客流量下的疏散过程,并进行讨论,提出改进人群疏散效率的措施。研究结果表明:Pedynamics软件采用前后端分离的架构进行模块化开发,易于升级维护;后端采用的人群疏散计算模型结合了人群疏散动力学特别是人员有限理性路径选择行为方面的研究成果,能够真实体现行人的疏散行为特征;软件前端的场景预处理界面能够帮助用户简单、快速地基于图纸构建疏散场景,可视化及数据统计模块支持多视角查看模拟结果和疏散数据,提高工程应用的效率。研究结果可为人群疏散风险评估提供技术支持。

Micro-Doppler effect testing technique for attitude of projectile in space flight

To measure projectile attitude in space flight, based on continuous wave （CW） radar, a new micro-Doppler effect testing technique is developed in this paper. It also establishes radar testing model for attitude of flying projectile and resolve micro-Doppler effect of projectile motion attitude. By distinguishing and geting attitude parameters such as micro-motion period, this technique can in- tuitively estimate the flight stability of projectile, and the validity of this technique is proved accord- ing to flight tests.

美国MicroE圆光栅在数控转台和DDR电机领域的应用及特点

近年来,对精确自动测量转角的要求大大增长,作为自动测量仪器和装备的关键元件圆光栅及反馈系统的需求也日趋迫切。很多部门在精密加工、精密测量和自动控制等方面,使用圆光栅就可以实现自动测量、数显和数控。

综合物探在矿山深部资源勘查中的应用

矿产资源是社会和经济发展必不可少的物质基础,目前国内多数老矿山面临已探明储量枯竭的严峻形势,现有的勘查知识和技术难以解决矿山找矿勘查所遇到的特殊难题。针对矿山找矿的特殊性,本文结合安徽省霍邱某矿区的地质及物探资料,在采矿区选取典型剖面进行重磁、微动及可控源音频大地电磁法(Controllable Source Audio Magnetotelluric Method,CSAMT)。以微动和音频大地电磁数据分析推测浅部矿体采空及塌陷区;在深部将微动勘探与重力数据结合,取长补短,通过剪切模量将微动视横波速度与地下介质密度直接联系起来,经已知矿体位置剪切模量的分布规律并结合重磁反演在300 m以深推测了两条近平行层状分布的矿体,矿体长200~250 m,最厚处约50 m;在标高100~200 m的类似S形褶皱拐点处可能为成矿有利位置;同时推测已知主矿体在底板以深还有延伸。通过本次工作,证实了在当前老矿区内,将新技术微动勘探与传统物探方法相结合,各取其长,能提高矿山深边部及外围隐伏矿床(体)定位预测的有效性,挖掘新的找矿潜力。

一种无附加运动二级缩小微动系统设计及性能分析

为实现更小缩小比进而获得更高运动精度的灵活运动空间,设计了一种无附加运动的二级缩小微动机构及压电陶瓷致动器组成的微动系统,并对其驱动性能、运动性能和动态性能进行研究。基于柔性铰链杠杆原理及附加运动平衡原理,设计了一种无附加运动的二级缩小微动机构,可实现输入位移精密缩小;采用压电陶瓷致动器驱动二级缩小微动机构,组成二级缩小微动系统;采用有限元法完成系统驱动性能、运动性能及动态性能分析,实验法完成系统驱动性能及动态性能分析。分析结果显示,微动系统驱动具有线性度高、误差小等优点,系统具有优良的定位性能,系统动态性能良好且在运动过程中不会发生共振。研究对微动系统设计及性能分析具有重要的参考价值。

The Study on the Strong Ground Motion Attenuation Relationship in the Pishan Area,Xinjiang Uygur Autonomous Region

Small earthquake data from the Pishan MS6.5 aftershocks is collected by the Xinjiang Regional Digital Seismic Observation Network.Five parameters of the focal region are obtained by micro genetic inversion:stress dropΔσof 75.95 bars,quality factor parameters Q0of 186.33 andηof 0.26,geometric attenuation parameters R1of 72.18km and R2of 139.70km.We calculate the Fourier spectrum and combine it with the random phase spectrum to get the ground motion time history,and build the strong motion acceleration attenuation relationship.The strong ground motion acceleration attenuation of the Pishan area is thus obtained.Because of the insufficiency of strong ground motion records,we added the records from the Wuqia MS6.9 earthquake on October 5,2008,the Akto MS6.2 earthquake on October 6,2008,and the Lop MS6.0 earthquake on March 9,2012 to the data.The comparison of the calculation results and the empirical attenuation relationships with strong ground motion records reveal that the strong motion data of Pishan and Lop earthquakes is higher than the empirical attenuation relationships.The Wuqia MS6.9 earthquake strong motion data is consistent with Yu Yanxiangs(2013)short axis result,and lower than the present result.

Relativity and impossibility of superluminal motion

I prove that not only particle motion but also wave propagation cannot be faster than light according to relativity.

基于液压放大的压电微动平台设计与试验

针对传统微动平台难以满足微/纳米定位的要求,该文结合液压放大原理,提出一种基于液压放大的两自由度压电微动平台,并对其进行了结构设计。采用正交设计方法对其进行有限元双向流固耦合分析,优化了其结构参数。研制了实物样机并进行试验研究。开环控制试验结果表明,当压电驱动器输入为90μm时,压电微动平台最大输出位移为603.0μm,放大倍数约为6.7;闭环控制试验结果表明,采用分段微分、积分、比例(PID)算法能降低超调量,且响应时间、稳态时间均减小,稳态误差降低(为±0.2μm),实现了微动平台的大范围输出精密定位。

A novel MAV with treadmill motion of wing

The Magnus effect is well known phenomena for producing high lift values from spinning symmetrical geometries such as cylinders, spheres, or disks. But, the Magnus force may also be produced by treadmill motion of aerodynamic bodies. To accomplish this, the skin of aerodynamic bodies may circulate with a constant circumferential speed. Here, a novel wing with treadmill motion of skin is introduced which may generate lift at zero air speeds. The new wing may lead to micro aerial vehicle configurations for vertical take-off or landing. To prove the concept, the NACA0015 aerofoil section with circulating skin is computationally investigated. Two cases of stationary air and moving air are studied. It is observed that lift can be generated in stationary air although drag force is also high. For moving air, the lift and drag forces may be adopted between the incidence angles 20° to 25° where lift can posses high values and drag can remain moderate.