Development of electrorheological chip and conducting polymer-based sensor

This paper presents the development of an integrated sensor using two types of smart materials: electrorheological (ER) fluids and conducting polymers (CPs). The developed ER chip worked as an actuator, and it was driven by different voltages and control frequencies. When the four electrodes are controlled synchronously, the diaphragm acts as a vibrator whose frequency can be adjusted in accordance with the frequency of the electrical signals. The response signals of the CP sensor were recorded, and its properties were analyzed. Experimental results show that the amplitude decreases monotonically when the frequency increases, owing to the time delay in the pressure buildup in the ER chip. However, the displacement fluctuation of the diaphragm below 20Hz can be detected clearly even if the value is very low. When the vibration frequency is larger than 20Hz, the CP sensor can hardly detect the displacement fluctuation. Thus, the upper limit frequency that the CP sensor can detect is about 20Hz. The practical applications of this microdevice are also discussed.     

Development and evaluation of a two-axial shearing force sensor consisting of an optical sensor chip and elastic gum frame

We developed a promising shearing force sensor that is small in size and can measure shearing force along two axes independently. This sensor consists of an elastic gum frame and an optical sensor chip (6 mm × 6 mm × 8 mm). From the experimental results, the resolutions of the sensor along the x- and y-axes are found to be 0.070 N and 0.063 N. We also experimentally demonstrated that the sensor can separately measure shearing force along two axes. Finally, we demonstrated that the scale factor which correspond to resolution and linear portion which correspond to measuring range of the signals can be changed easily by using three types of elastic gum frame. This sensor can be embedded in the finger of a robot hand and use it to not only measure shearing force but also detect the slip phenomenon.     

基于单片机的电容传感器测量油箱油量方法的研究

介绍了一种基于单片机的电容传感器测量飞机油箱内油量的方法,利用电容式传感器的电容随油面高度的变化,构建了以单片机为核心的油量自动测试系统,给出了该油量测试系统的测量原理、硬件设计和软件设计。实际应用表明,该油量测量系统具有结构简单、测试精度高、可靠性好等优点。     

基于空间光耦合系统的芯片温度传感器

研究了一种硅光子芯片空间光耦合系统,简化了集成光子芯片用光纤阵列耦合的方式,通过将1 550 nm附近波段的光通过空间光学系统,经光栅耦合器垂直耦合进入集成光子芯片,经过波导与微环谐振腔实现光学传感,采用多模光纤收集出射能量,并进行温度传感测试。实验结果表明,用波长探测方式,得到自由光谱范围（FSR）为0.85 nm,Q值为16 321的环形谐振腔直通端透射谱线。在温度传感测试中,其灵敏度达到127 pm/℃。通过进一步对比测试表明,空间光耦合与光纤阵列光耦合只在插入损耗方面有所差距,耦合系统可得到较好的温度传感测试结果。空间光耦合具有更换传感器芯片便捷,容易实现多通道测试等优点。     

基于单片机实现FBG传感器的数据采集

介绍了基于单片机实现光纤Bragg光栅(fiber Bragg grating,FBG)传感器的数据采集系统的实现原理、硬件结构和软件设计.为了实现对FBG传感器的数据采集,采用美国Silicon Labs公司生产的C8051F020单片机对经过可调谐F-P腔解调后的波长进行采集,对得到的数据进行分析处理.实验结果表明该系统可满足井下实时采集的要求,为井下实时采集系统提供可靠的现场测试工具.     

Development of a laboratory test device for electrorheological fluids in hydrostatic lubrication

Electrorheological (ER) fluids exhibit changes in their rheological behaviour in the presence of an external electric field. Research and development activities related to ER fluids and their applications have increased dramatically during the last few decades. If commercialised, ER fluids could have a significant impact on hydraulic equipment, and be utilised in the automotive, marine, aerospace, robotics, and machinery industries. The objective of the present study is to demonstrate the feasibility of using ER fluids to produce ‘smart’ lubricants that can control friction and wear of sliding components. The ER lubricant effect is demonstrated using a unique test machine that utilises hydrostatic lubrication. It is found that the friction torque increases by as much as 30% when a voltage of 2000 V is applied to an ER fluid in the newly developed test machine.     

低电压集成电泳芯片的研制

电泳芯片是一种重要的微型分析仪器。针对目前电泳芯片分离电压高、难以实现真正的一体化集成等问题,利用在分离通道上分段、交替、循环施加电压的方法提出了电泳芯片低电压分离的模型。依据该模型对这种低电压集成电泳芯片的研制工艺和控制系统进行了研究,研制出了相应的样品。初步实验表明,该电泳芯片的低电压分离的思想可为分析仪器的集成化、便携式设计提供一定的方法。     

基于单片机的光纤Bragg光栅传感器的解调系统

长期以来,对光纤Bragg光栅传感器反射波长的检测是采用光谱仪,随着光纤Bragg光栅传感器应用的不断发展,光谱仪表现出越来越多的局限性.本文利用调谐法布里-珀罗腔多光束传播,当法布里-珀罗腔满足特定条件时其透射光可达到最强或最弱原理,建立了F-P腔解调系统模型,通过检测F-P腔的相关参数而得到所测的参变量;根据光纤Bragg光栅自身特性,建立了匹配滤波法解调系统模型,应用另一光纤Bragg光栅跟踪被测光纤Bragg光栅的变化,从而得到所测量;论文指出了应用时在这两种解调方案中需要解决的关键问题.为了提高系统测量的准确性和实时性,系统采用单片机系统处理相关数据信息.本文系统详细阐述了在解调系统中单片机的应用及相关接口模型,给出了详细的软硬件设计.     

Development of web-based machining chip breaking prediction systems

The prediction of chip breaking in machining is an important task of automated manufacturing. A chip breaking predictive model has been developed to predict the chip breaking behaviour in steel turning with grooved tools. The model is based on the chip breaking limits theory. A web-based chip breaking prediction system has been developed and presented in this paper with industrial application examples. With the system, the chip breaking range in steel turning with grooved tools can be predicted under different cutting conditions. The experimental data for turning different steel material over a wide range of feed rates, cutting speeds and tool geometry showed agreements with the model prediction. The user-friendly system is accessible through the Internet for the purposes of cutting condition design and tool selection. Also, the system can easily be extended to contain new cutting tools and new workpiece materials with a small number of cutting tests.Nomenclature f Feed rate (mm/rev) - d Depth of cut (mm) - V Cutting speed (m/min) - f_cr The critical feed rate (mm/rev) - d_cr The critical depth of cut (mm) - r Insert Nose radius (mm) - W_n Insert chip breaking groove width (mm) - Cutting edge angle (deg) - ₀ Insert rake angle (deg) - ₀₁ Insert land rake angle (deg) - b₁ Insert/chip restricted contact length (mm) - _s Insert inclination angle (deg) - h Insert backwall height (mm) - WP Work piece - DB database     

Simulation and experimental study of the sensor emitting frequency for ultrasonic tomography system in a conducting pipe

Ultrasonic tomography techniques provide flow visualization capability, non-invasively and non-intrusively, to enhance the understanding of complex flow processes. There is limited ultrasonic research in tomography imaging systems in the tomogram analysis of fluid flow in a conducting pipe because of a high acoustic impedance mismatch, which means that very little ultrasonic energy can be transmitted through the interface. The majority of industrial pipelines are constructed from metallic composites. Therefore, the development and improvement of ultrasonic measurement methods to accommodate a stainless steel pipe are proposed in this paper. Experimental and simulation distribution studies of the ultrasonic emitting frequency in acrylic versus stainless steel pipes were studied, measured and analyzed. During the simulation, ultrasonic transducers were placed on the surface of the investigated pipe to inspect the ultrasonic sensing field. The distribution of the sound wave acoustic pressure was simulated based on the physical dimensions and parameters of the actual experimental hardware set-up. We developed ultrasonic acoustic models using the finite element method with COMSOL software, and experiments were carried out to validate the simulation results. Finally, by performing the static phantoms tests, a feasibility study of ultrasonic tomography system was presented to investigate the void fraction of liquid column inside a stainless steel pipe.     

Development of a profile gauging sensor

A non-contact inspection system that can automatically assess the quality of complex engineering components such as turbine blades, has been identified by the aeroengine industry as a requirement in automating the process of proof inspection. This requirement led Rolls-Royce plc. and Imperial College to investigate non-contact measurement techniques and to devise an automated system based on such technology. The system in its final form, will provide an integrated CAD/CAM-based concept that will enable design and manufacture data relating to complex three-dimensional objects to be compared and assessed.     

Expressions for coefficients of electrorheological fluid dampers

Useful expressions are developed for the damping coefficient of two types of viscous dampers that contain electrorheological (ER) fluids. The damping action in the first type occurs in flow between stationary parallel plates; the second type has annular flow between two stationary concentric cylinders. For ER fluid control, an electric field is applied across the gap in which the fluid flow occurs. The solution for the concentric cylinder damper is based on a thin gap approximation. These solutions may facilitate solving mechanical systems problems, using ER fluids, and demonstrate the controllability of ER dampers.     

圆盘式电流变离合器的动态特性

研究圆盘式电流变传动机构的动态特性，利用神经网络进行系统识别，并采用NI虚拟仪器对机构进行检测和控制，分析输出转矩与所加电场的关系，推动电流变流体传动机构的应用。     

ER智能阻尼器的试验研究

对ER智能阻尼器的结构设计、阻力公式推导简要介绍的基础上,通过改变其电流变液的种类、电压的大小、电场的面积以及电极间的距离等结构参数,对所设计的电流变智能阻尼器进行了试验研究,分别测定了阻尼器阻力的变化。试验结果及分析对ER智能阻尼器的结构设计有重要的参考价值。     

微米级电容式静力水准器设计及标定研究

基于当前高能同步辐射光源(HEPS)装置的沉降监测需求,课题组设计关键参数和结构,研制了国内首个微米级单极板电容式静力水准器样机。本文重点研究该水准器的标定和精度验证,针对传统的标准量块和位移台标定法存在标定精度低、机械加工要求高等问题,创新性采用单水准器直接标定法和多段拟合参数获取方案,实现10 mm量程的微米级标定;同时提出采用激光反馈干涉仪联合纳米级位移台直接监测液位变化,实现单水准器的全量程精度验证,精度3μm;通过重载位移台进行了7 m距离的两点监测系统的精度验证,在10 mm量程内相对高程监测精度可达到5μm。结果表明样机精度符合设计要求,可为我国大型装置的高精度高程向监测提供可靠手段。     

高速CCD激光位移传感器

介绍了一种用于高速测量的CCD激光位移传感器测量系统,可用于高速、实时地测量运动物体的位移或高速振动.传感器测量系统由光学系统、7 500像元的高速线阵CCD、转换速率达40 MHz的高速ADC、高速缓存FIFO、比较器筛选电路、CPLD时钟驱动电路、像元脉冲计数器和数字信号处理器(DSP)构成.系统采用自适应控制方法,通过调节激光的发射频率和输出电流强度来调节发射激光光强,从而适应各种被测对象和外界环境条件.采用特殊设计的比较器筛选电路来控制FIFO对高速A/D采样数据的存储和DSP对高速FIFO中数据的读取,使FIFO只存储CCD输出的有效像元信号,从而减轻DSP数据处理的负担,实现对CCD传感器信号的采集与处理同时进行,满足高速测量的需要.实验结果表明,数据转换速率可达40 M,最小采样间隔时间为0.1 ms,位移分辨率为0.01 mm,重复性为0.01 mm.     

Development of an air servo displacement sensor

This paper introduces a new type of displacement sensor called an “air servo displacement sensor.” The sensor’s piston automatically follows a measured object using a pneumatic servomechanism with a nozzle-flapper that acts as a detecting device. Because the piston is supported by an aerostatic bearing, it experiences almost no friction. An optical linear scale mounted on the piston is used to measure the displacement of the measured object because the gap between the nozzle and the measured object is maintained at a constant level. As a result, this new sensor can successfully perform non-contact displacement measurements over a much longer measuring range, when compared to the traditional air micrometer. The optimal parameters for the sensor structure were obtained using simulations and experiments. Performance accuracy tests with a micrometer showed a repeatability error below ±0.5 μm and a linearity error below ±2 μm, with a measuring range beyond 10 mm. It has been verified that that the sensor exhibits a sufficient level of accuracy for the operational requirements.