基于光波导的传感驱动一体化软体康复手

针对刚性手功能康复外骨骼机器人适应性差,存在安全隐患问题,该文设计了基于光波导的传感驱动一体化软体康复手控制系统,用于辅助患者手部的康复。通过顺应性融入自制柔性光纤传感器使手指弯曲角度和气腔内压力的反馈信号更加精准。其次,采用一体化多腔室手指的设计方法,使不同手指不同关节弯曲,其结构简单、易于控制,具有良好的被动柔性。然后,结合柔性光纤传感器对软体康复手进行闭环反馈控制,使手部动作更加灵活。最后,实验结果验证了基于光波导的软体手部康复机器人控制系统整体结构小型化,且柔顺性高,患者穿戴更方便。     

基于外骨骼的可穿戴式上肢康复机器人设计与研究

为辅助对患肢进行高强度标准化康复训练工作,研制了一种基于外骨骼原理的可穿戴式4自由度上肢康复机器人.该康复机器人可实现肩关节水平方向外展/内收、竖直方向上摆/下摆和旋转运动以及肘关节的屈/伸运动.首先根据康复医学原理确定出人手臂各关节的运动角度范围,并在确保驱动力矩最小的原则下进行结构设计.然后,对各结构进行了运动学与动力学仿真分析,并据此对结构进行优化.最后,设计了康复机器人在连续被动康复运动(CPM)模式下的控制系统.实验结果表明,此结构方便穿戴于人体,机器人的运动自由度与人体运动自由度同轴,能有效地对患肢前、后臂各部位进行支撑和牵引,精确地施加牵引力于上肢的各关节.     

TPMS硅基压阻式压力传感器的研制

:轮胎压力监测系统(TPMS)对压力传感器越来越大的市场需求使得这类传感器再次成为一个研究热点.商业领域对新一代压力传感器的要求是小尺寸、高性能、低价格,针对在30 μm厚度的硅杯方形薄膜上采用新型折线形状和位置的压敏电阻,设计并制作了一系列压阻式压力传感器.分析和讨论了膜的面积、电阻形状和位置等参数对压力传感器的灵敏度和线性度的影响.测试得到1000 kPa量程下边长为370μm的压力传感器灵敏度和线性度分别为15.5 mV/V·FS、0.012%/FS;边长为470μm的传感器的灵敏度和线性度分别为32.2 mV/V·FS、0.078%/FS,满足TPMS应用标准.这种器件体积小、成品率高,灵敏度和线性度均得到提高,也可用于医学、航空等其他领域.     

线驱无关节手指外骨骼的运动耦合方法

传统的无关节手指外骨骼线缆驱动方法在实施过程中会产生远端关节先于近端关节运动的错误动作顺序.为弥补该缺点,本文利用一对耦合的线缆,提出了一种面向无关节手指外骨骼的线缆驱动运动耦合方案——通过刚柔线缆的交叉使用避免了弯曲方向和伸展方向之间的运动干涉,并在保持传统无关节手指外骨骼驱动方案的简洁紧凑特点的同时使其能够输出正确的运动顺序.阐述了所提方案的工作原理,并对其进行了仿真分析;开发了实验假手并依照假手数据设计外骨骼零件,构建了实验平台,完成了运动耦合的运动学实验,验证了本文方法的正确性和可行性.     

下肢负重外骨骼机器人的初步设计

研究设计了一种能够增强人体负重的下肢外骨骼机器人,该负重外骨骼机器人具有8个自由度,可实现髋关节的外展与内收、屈/伸运动;膝关节的屈/伸运动以及踝关节的弯曲运动;根据人体步态分析研究出各个关节的运动角度范围,结合目标负重进行结构优化设计;对机器人的结构进行简化,建立了外骨骼机器人的连杆模型,根据其几何关系,采用D-H准则对外骨骼机器人进行了数学建模;以计算机、六轴运动控制卡和STM32为核心构建了控制系统,结合ZMP (zero moment point)零力矩点稳定性判据及三次样条插值进行了步态规划,并将此步态规划应用于样机上;样机实验结果表明,此结构能够满足不同体型的人进行穿戴,并能够根据规划的步态轻松行走,验证了其结构和控制系统的合理性.     

硅悬臂梁脉象传感器温度补偿

阐述了采用硅悬臂梁制造的脉象传感器结构、设计和温度补偿原理。实验结果表明:补偿后的传感器具有灵敏度高、稳定性好,线性度为1%FS(0~5 N),重复性为0.5%FS,灵敏度为50 mV/N。给出的温度补偿晶体管对该脉象传感器的灵敏度温度漂移补偿效果好,有推广应用前景。     

单片三轴大量程加速度传感器性能测试与分析

对设计的单片三轴MEMS大量程加速度传感器进行了马歇特锤冲击测试和Hopkinson杆冲击校准试验,得到了三轴加速度传感器冲击过载信号及其各轴向的横向灵敏度比、线性度等关键参数。测试结果表明该三轴传感器在受到117 395.95 gn以上的冲击信号作用时,传感器各轴仍然能够正常工作;其三轴轴向灵敏度均能达到0.1μV/gn以上,各敏感轴受到轴向加速度时其线性度小于6%,轴间横向灵敏度比小于10%。     

高线性度离子皮肤手指关节弯曲角度传感器

针对柔性传感器用于手指关节弯曲角度测量范围有限和线性度不高的问题,制备了一种透明的离子皮肤手指关节弯曲角度传感器.该传感器由具有拉伸率大、保水性高的氯化锂离子凝胶电极和硅橡胶薄膜构成.建立传感器的角度传感理论模型,测试传感器电容信号与手指关节弯曲角度的关系.试验结果表明,该传感器可以测量手指关节全运动范围内的角度,线性...     

MEMS粗真空传感器研制

设计了硅基MEMS粗真空传感器及其工艺流程,分析了 MEMS粗真空传感器的工作原理和过程,制作了MEMS粗真空传感器,并对其真空敏感特性和温度交叉敏感特性进行了实验研究.研究结果表明:采用恒压源供电时,制作的MEMS真空传感器灵敏度高达0.55μV/Pa,同时,具有很好的线性度和重复性.     

齿轮传动型光纤弯曲损耗位移传感器及其实验研究

针对传统光纤弯曲损耗位移传感器线性度不高的问题,设计了一种齿轮传动型光纤弯曲损耗位移传感器,并用理论证明了被测位移量与光纤弯曲损耗之间呈线性关系,并进一步做了实验研究.实验结果表明,本传感器的灵敏度与理论计算结果相符,并具良好的线性度与测量精度,便于在实际工程中应用,有有着较好的市场应用前景.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).