磁性液体倾斜角传感器的有限元耦合分析

根据一种差动式变压器结构的磁性液体倾斜角传感器工作原理,推导出传感器输出电压与灵敏度公式,并利用ANSYS软件对这种结构的传感器进行电磁-电路的耦合场分析,通过对数值模拟结果进行深入分析以便能为传感器的设计提供指导,并将模拟结果与已公开发表的实验数据进行对比.得出当磁性液体倾斜角传感器的结构参数确定后,传感器的输出电压与转动角度成线性正比关系;且传感器的灵敏度与激励电压的振幅、磁性液体相对磁导率及激励电压频率成正比,但激励电压频率超过一定范围后,传感器灵敏度增加值会逐渐减小,建议激励电压频率最好不超过1.5 kHz.     

基于堵塞原理的变刚度软体机器人设计与试验

软体机器人运动时具有高柔性,执行任务时又能展示出强刚度,在军事侦察、灾难救援等复杂环境探索与检测方面具有重要的应用价值。结合主动驱动的网络气动结构与被动驱动的堵塞机构的优势,提出实时变刚度的软体驱动器,研究其变刚度机理和动态建模方法。首先,提出了气动-堵塞机构耦合的软体驱动器模型;其次,利用赫兹接触模型,建立机器人运动数学模型,从理论上研究其变刚度形成机理;再次,利用有限元对气动驱动结构进行分析,研究空腔内压强、形状和大小对软体机器人弯曲角度的影响,并进行了优化;最后,制作了变刚度软体机械臂样机,验证了软体驱动器的变刚度性能与运动性能。该研究有望为变刚度软体机器人设计与刚度调控提供新的理论和技术支持。     

TriMule与Tricept机器人刚度解析与比对

为分析比对TriMule机器人与Tricept机器人中两种1T2R并联机构的刚度性能,基于旋量理论,通过力/变形雅可比将支链层面的界面刚度矩阵映射为机构末端笛卡尔刚度矩阵,构造出二者的刚度半解析模型。在此基础上,结合两种1T2R并联机构为球坐标机构的构型特点,推导出二者在给定参考位形下切向线柔度特性各向同性条件的显式表达,并提出评价两种机构切向、法向柔度特性的局部与全域刚度性能评价指标。利用该模型,揭示出两种机构中主动与从动支链的夹角对局部和全域刚度性能的影响规律。研究结果表明,对于一组相同的尺度、结构和任务空间参数,两种机构的刚度性能相当,且其局部与全域刚度性能均是强线性相关的,进而可用前者准确地表征后者。     

基于加权移动平均的姿态角测量技术实现

在深入研究基于二维传感器测倾角技术的基础上,分析了利用三维传感器测姿态角的原理方法,该方法可减小因二维传感器单轴或双轴输出带来的随机性系统误差,可实现同时对倾角与滚转角的测量;在后续的数据处理方法选择上,运用了基于加权移动平均平滑滤波的修正方法,并在仿真与实验中得到了验证,提高了数据的精度,取得了较好的效果,为特殊行业的测姿提供了理论支持。     

车辆行驶过程中的状态估计问题综述

从传感器配置、估计用物理模型、状态估计算法和估计过程中的模型参数自适应4个方面回顾车辆行驶过程中的状态估计问题.对比分析以纵向车速、横摆角速度、质心侧偏角为估计目标时传感器的常见配置,给出合理的传感器配置方案;比较在不同估计目标下运动学模型和动力学模型的优缺点,提出纵向车速和横摆角速度适合采用运动学模型、质心侧偏角估计适合采用动力学模型的观点;列举并比较车辆状态估计中常用的估计算法,给出各算法在实际应用中所需注意的因素.指出实现估计过程中的参数自适应是提高不同行驶工况下观测器估计精度的有效手段,并介绍递推最小二乘、联合卡尔曼滤波等实现参数自适应的典型方法.     

可穿戴式电子织物仿生皮肤设计与应用研究

为满足电子仿生皮肤的穿戴舒适度,提出了一种电容式柔性织物压力传感器,采用丝网印刷工艺,以织物为柔性基体,炭黑填充型复合弹性电介质和有机硅导电银胶制备柔性压敏触觉单元。介绍了压敏单元的结构设计与感知机理,研究了炭黑含量与温度对织物触觉单元性能的影响,改善了该电子织物的输出线性度与重复性,实现了0~700 k Pa量程范围迟滞误差为5.6%,动态响应时间为89 ms,灵敏度为0.025 36%/KPa,同时,引入温度补偿以提升触觉感知准确性。通过将织物压敏单元应用于足底压力信息的时空分布研究和机械手的软抓取实验,其足底压力分布及触觉感知实验结果表明,该电容式柔性织物压力传感器具有良好的工作稳定性与触觉感知功能,为可穿戴式人工皮肤的研究提供了一种设计方案。     

变频式差胀涡流传感器的研制

为了配合汽轮发电机组状态监测系统中的差胀测试要求,研制了变频式差胀涡流传感器.介绍了变频式涡流传感器的工作原理,根据测出的位移与频率的关系数据,提出了一种线性化数学模型.设计了传感器测量电路,探讨了消除材料敏感性的方法,并对变频式差胀涡流传感器进行了标定和相关性能测试.该传感器的优点是可以提供频率和电压两种信号输出,频率输出可以有效提高信号传输的抗干扰能力,便于数据采集和处理,而电压输出则可以直接得到位移量.现场实验结果表明,变频式差胀涡流传感器分辨率和精度高,抗干扰能力强,性能稳定可靠.     

用于假手指尖的光纤光栅触觉力传感器研究

针对现有假手触觉测量常用的薄膜压力传感器精度不佳、线性度差、迟滞性高等问题,研究了一种可安装于假手指尖的光纤布拉格光栅触觉力传感器。首先,通过传感单元的微小化结构设计,可以将施加的外力转化为光纤承受的轴向力;进而,通过有限元对传感器结构参数进行优化,提高了光纤光栅对于压力的灵敏度;然后,围绕假手指尖应用的需求,制作了这种光纤布拉格光栅触觉力传感器;最后,对该传感器进行了性能标定、对比分析和应用抓取3个实验分析,实验结果表明:该传感器压力灵敏度为0.103 8 nm/N,线性度R~2为0.998,重复性误差为1.32%和迟滞性误差为2.19%;与现有的薄膜压力传感器对比,该传感器的线性度和重复度都更高,迟滞性更低。     

基于机械放大式机构的新型纳米位移传感器设计

为了能有效地检测PZT驱动器纳米级的驱动位移,文章提出一种采用基于柔性铰链的多级杠杆放大原理的新型纳米位移传感器。与前三代纳米位移传感器相比,新型传感器采用差动结构以及圆筒状的外形,传感器的这种独特结构赋予其较大的机械放大比;同时,建立了其理想数学模型并计算了机械放大比。为了证明传感器的有效性,对其进行了有限元仿真分析。分析结果表明新型纳米位移传感器具有较大的应变输出,且其位移分辨率将小于3 nm。     

Development of a tactile sensor array with flexible structure using piezoelectric film

This research is the development of a flexible tactile sensor array for service robots using PVDF(polyvinylidene fluoride) film for the detection of a contact state in real time. The prototype of the tactile sensor which has 8X8 array using PVDF film was fabricated. In the fabrication procedure, the electrode patterns and the common electrode of the thin conductive tape were attached to both sides of the 28/im thickness PVDF film using conductive adhesive. The sensor was covered with polyester film for insulation and attached to the rubber base for a stable structure. The proposed fabrication method is simple and easy to make the sensor. The sensor has the advantages in the implementing for practical applications because its structure is flexible and the shape of the each tactile element can be designed arbitrarily. The signals of a contact force to the tactile sensor were sensed and processed in the DSP system in which the signals are digitized and filtered. Finally, the signals were integrated for taking the force profile. The processed signals of the output of the sensor were visualized in a personal computer, and the shape and force distribution of the contact object were obtained. The reasonable performance for the detection of the contact state was verified through the sensing examples.     

模式选择阀门可调机构运动仿真分析

利用几何方法建立了基于曲柄滑块构型的模式选择阀门可调机构的滑块位移输入与阀门角度输出的关系,并对其进行了运动分析及精度分析。应用多体动力学仿真软件ADAMS建立了模式选择阀门可调机构的仿真模型,对其进行了刚体仿真,仿真结果与理论分析结果几乎一致,互相验证了数学模型与仿真模型的正确性。另外,当联动环为柔性时对其可调机构进行了柔性体仿真,分析了联动环在不同刚性下对各阀门输出同步性的影响,仿真结果表明,提高联动环的刚性能够提高各阀门输出的同步性。     

具有应变式触觉传感器的机器人柔顺指端

针对机器人抓握处于重力场中的等截面均质杆件操作,提出一种具有应变式触觉传感器的机器人柔顺指端的结构。在机器人平行抓握中,利用金属弹性薄板做弹性元件,应变片做触觉触感单元,实现对物体的长度和质量的感知,在指端的表面封装电流体实现软／硬抓握,另外,着重讨论了抓握系统的传感原理,试验表明,这种机器人指端具有良好的识别能力和稳定抓握能力。     

Magnetic resonance imaging-compatible tactile sensing device based on a piezoelectric array

Minimally invasive surgery is a widely used medical technique, one of the drawbacks of which is the loss of direct sense of touch during the operation. Palpation is the use of fingertips to explore and make fast assessments of tissue morphology. Although technologies are developed to equip minimally invasive surgery tools with haptic feedback capabilities, the majority focus on tissue stiffness profiling and tool-tissue interaction force measurement. For greatly increased diagnostic capability, a magnetic resonance imaging-compatible tactile sensor design is proposed, which allows minimally invasive surgery to be performed under image guidance, combining the strong capability of magnetic resonance imaging soft tissue and intuitive palpation. The sensing unit is based on a piezoelectric sensor methodology, which conforms to the stringent mechanical and electrical design requirements imposed by the magnetic resonance environment The sensor mechanical design and the device integration to a 0.2 Tesla open magnetic resonance imaging scanner are described, together with the device's magnetic resonance compatibility testing. Its design limitations and potential future improvements are also discussed. A tactile sensing unit based on a piezoelectric sensor principle is proposed, which is designed for magnetic resonance imaging guided interventions.     

基于神经网络的光纤布拉格光栅触觉信号解耦研究

针对应用于电子皮肤的柔性光纤布拉格光栅触觉传感器的输出信号是施加载荷位置、大小等信息的非线性、多维耦合问题,在对光纤布拉格光栅触觉传感阵列进行力学有限元仿真的基础上,提出了将误差逆传播神经网络和径向基函数神经网络应用于仿真和实验的触觉信号解耦方法。对实验数据的神经网络解耦结果表明,相对于误差逆传播神经网络,径向基函数神经网络具有更强的抗噪声能力,能够更好地逼近含有噪声的触觉多维非线性实验数据之间的映射关系。经径向基函数神经网络解耦后,传感器阵列的空间分辨率为5 mm,对压力位置和大小感知的最小相对误差为3.00%和4.82%。本文的研究成果对开展电子皮肤柔性触觉传感器的研究和推广具有一定的实用价值。     

SOFT SENSING MODEL BASED ON SUPPORT VECTOR MACHINE AND ITS APPLICATION

Soft sensor is widely used in industrial process control. It plays an important role to improve the quality of product and assure safety in production. The core of soft sensor is to construct soft sensing model. A new soft sensing modeling method based on support vector machine (SVM) is proposed. SVM is a new machine learning method based on statistical learning theory and is powerful for the problem characterized by small sample, nonlinearity, high dimension and local minima. The proposed methods are applied to the estimation of frozen point of light diesel oil in distillation column. The estimated outputs of soft sensing model based on SVM match the real values of frozen point and follow varying trend of frozen point very well. Experiment results show that SVM provides a new effective method for soft sensing modeling and has promising application in industrial process applications.     

基于霍尔效应的车用角位置传感器线性化研究

线性度是传感器的重要性能指标之一。基于霍尔效应的霍尔角位置传感器的霍尔输出电压可表达为:UH=KHBIcosθ,霍尔输出电压与被测角度θ之间的关系是非线性的。针对角位移变化引入的非线性变量cosθ使得普通的磁场结构难以实现霍尔角位置传感器较大范围线性输出的问题,本文提出了一种改进的车用霍尔传感器磁场结构,通过对改进后的磁场结构用有限元仿真计算和实验测量均得出改进后的磁场结构能够实现霍尔角位移传感器的霍尔输出电压与被测角度之间呈线性变化。     

ACTIVE ROBOTIC ENDOSCOPE FOR MINIMALLY INVASIVE SURGERY

A robotic endoscope is mainly composed of a tactile array sensor, soft mobile mechanism for earthworm locomotion and turning mechanism based on shape memory effect. The tactile array sensor can provide the information about magnitude and orientation of interacting forces between the robotic endoscope and the wall of gastrointestinal tracts. The soft mobile mechanism contacts gastrointestinal tracts with air-in inflatable balloons, so it has better soft and non-invasive properties. The turning mechanism can be actively bent by shape memory alloy components and conform to the complex shape of gastrointestinal tracts. The working principle of robotic endoscope is dealt with.     

Fiber optic surface topography measurement sensor and its design study

This paper presents some aspects of design approach, modeling, and experimental measurement results of a fiber optic-based surface topography measurement sensor that can measure surface roughness as well as the distance between the sensor tip and a surface and surface inclination angles. The working principle of the sensor is based on the detection of light intensity reflecting from the surface being measured. The sensor is very small and easy to operate. It can be attached to a coordinate measuring machine (CMM) to measure surface position coordinates, inclination angles, and surface roughness in a noncontact manner at one measurement setup. A theoretical model of intensity distribution and intensity detection has been established for the sensor. A three-factor and three-level experiment was designed to investigate the relationship between sensor performance and sensor design parameters. Two second-order regression models have been generated, which show that the central distance between the emitting and receiving fibers of a sensor has the strongest influence on the effective range of the sensor; whereas, the critical angle of a receiving fiber influences the sensitivity of the sensor most.     

基于纳米晶软磁合金的转矩、转速和转角多功能传感器研究

为提高传感器的多功能性,对一种可同时测量转角、转速和转矩的非接触式传感器进行了研究。首先,论述了传感器的结构和基于纳米晶软磁合金压磁效应的测量原理,然后推导出传感器的输出数学模型与灵敏度表达式。最后,在25～100℃温度范围、0～450N·m转矩范围及500～3525r/min范围内进行试验,得出相对于25℃的零点温度漂移为0.002 03%/℃(满量程),满量程最大线性度、重复度及迟滞静态误差分别为0.81%、0.50%、0.85%,转速最大相对误差为0.70%。试验数据还显示,该传感器的测量灵敏度为1.26mV/N·m,精度达到1.0%,对于一般工程应用是可行的。     

Linear calibration method of magnetic gradient tensor system

Based on the detailed analysis of systematic errors, mathematical model of error parameters is constructed and linear calibration method is proposed for magnetic gradient tensor system. Firstly, nonlinear mathematical model of error parameters for single vector magnetometer is constructed based on scalar calibration, and least square solution is deduced by two nonlinear conversions without any mathematical simplification. Then outputs of four tri-axial magnetometers are calibrated to sensor’s orthogonal coordinate respectively. Secondly, a least square estimation is proposed for the misalignment errors between different magnetometers according to the rotation matrix comprising conversion of different orthogonal coordinate system. After calibration, outputs of tri-axial magnetometers are acquired along the ideally platform frame-orthogonal coordinate system and these enable calibration of magnetic gradient tensor system. Simulations and experiments show that the proposed linear calibration method can accurately solve the detailed error parameters and decrease measurement errors of magnetic gradient tensor system remarkably.