基于GMM的气动伺服阀和蠕动机械的实验研究

阐述了利用国产超磁致伸缩材料（GMM）研制的新型气动伺服阀和蠕动机械的结构及工作原理,并对它们进行了实验研究,实验结果表明：GMM气动了阀具有较宽的压力控制特性、良好的线性度和较快的响应速度;GMM蠕动机械结构简单,能可靠地实现双向控运动。     

尺蠖式直线微驱动器的设计

针对普通尺蠖式直线微驱动器运动速度低和输出力小等问题,基于柔顺机构设计了一种新型尺蠖式直线微驱动器。微驱动器由箝位机构、驱动机构和输出轴组成,其运动特点是驱动机构驱动箝位机构进行往复直线运动,箝位机构带动输出轴作直线运动。箝位机构和驱动机构均采用柔性杠杆结构,保证了微驱动器所需的箝位力与驱动力,并提高了其运动速度。采用伪刚体方法建立了驱动电压与箝位力、驱动机构输入位移与输出位移之间的关系,根据功能原理建立了输入力与驱动力之间的关系并制作了样机,搭建了实验测试系统进行性能测试,测试结果表明,驱动器最大箝位力为216.43N,最大驱动力为13.5N,在驱动电压120V,频率95Hz时,达到最大速度48.91mm/s。     

A Fully Autonomous Microrobotic Endoscopy System

In this paper, design of an autonomous microrobotic endoscopy system is presented. The proposed microrobotic endoscope is a vision-guided device, developed to facilitate navigation inside a human colon. The design of the entire system is divided into three areas viz. design of a microrobotic carrier, path planning and guidance, and an off-board control system. A microrobotic design based on pneumatic mechanisms to achieve locomotion and steering is explained. General mathematical analysis governing the differential steering of the robotic tip is also described. The path planning of the microrobot is carried out based on the sensory fusion utilising the quantitative parameters from the captured images and the tactile sensors. A real-time image segmentation scheme is described for extracting the lumen from endoscopic images. An off-board control system to control the directional movements of the microrobot is also explained. The proposed endoscopy system was tested with physical models and animal colons and the experimental observations are presented.     

Detecting small taxa using simulated comparison data: A reanalysis of Beach, Amir, and Bau's (2005) data.

On the basis of taxometric analyses of data sets that they created to pose interpretive challenges, S. R. H. Beach, N. Amir, and J. J. Bau (2005) cautioned that using comparison data simulated by J. Ruscio's programs can lead to inaccurate conclusions. Careful examination of S. R. H. Beach et al.'s methods and results plus reanalysis of their data fails to substantiate this concern: Using comparison data identified the taxonic structure of S. R. H. Beach et al.'s data sets, even when the taxon base rate was very low. The authors show that J. Ruscio's simulation programs generate comparison data appropriately and that analyzing these data provides a useful interpretive aid. Additionally, the authors discuss and illustrate the effective use of the inchworm consistency test to disambiguate taxometric results for small taxa and dimensional constructs with positively skewed indicators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

柔性框架式蠕动机构运动时的负位移现象

基于尺蠖运动原理,以压电陶瓷作为驱动和钳位元件,研制了柔性框架式蠕动机构。在计算机控制下,对其步进性能进行了测试,首先对比了六步和四步模式运动的效果,对机构运动中出现的负位移现象进行了深入分析;继而在四步模式下,研究了钳位电压和驱动电压对机构负位移的影响。研究结果对提高该进给机构的运动速度、运动精度有一定的指导意义。     

仿尺蠖爬壁机器人自适应吸附及摇杆控制

为了解决真空吸附爬壁机器人爬行时,需要吸盘和壁面紧密贴合,不易操控的问题。建立了吸盘足至壁面的空间几何模型;基于D-H参数,建立了运动学模型,根据速度运动学逆解,设计了一种用于对称机构爬壁机器人的摇杆操作方法,将摇杆轴映射为关节速度闭环;根据位置运动学逆解,设计了自适应吸附动作,吸盘足与壁面距离小于设定阈值时,自动触发自适应吸附动作;搭建了机器人控制系统和自适应吸附装置,在水平壁面上进行爬行实验,验证了该方法可减小操控难度。     

具有缩放平台的串并联蠕动机构*

为探索新型移动机构及其移动方式,提出一种具有缩放平台的串并联移动机构。该机构由两个空间3-RPR并联机构串联组成,其三个平台均为可缩放移动平台。通过三个平台依次缩放配合支链的伸缩,该机构可实现蠕动运动。该机构兼具并联机构高刚度和串联机构运动空间大的优势。应用螺旋理论计算该机构的自由度,运用矢量法进行运动学分析。以攀爬管道内壁为应用案例,介绍该机构蠕动的详细步态。利用Solidworks进行详细的机械设计。利用ADAMS进行攀爬管道的动力学仿真,得到平台的位移曲线以及支链推杆的杆长变化曲线。制作一台原理样机,验证了该机构的自由度特性和蠕动步态。     

一种GMM蠕动微位移机械控制节拍方法

针对超磁致伸缩材料蠕动微位移机械在位移过程中的控制节拍问题,文章研究四节拍运动和六节拍运动,并根据仿生原理,由尺蠖运动规律,设计了以单片机为核心的控制器硬件和软件。通过比较两种节拍运动,情况表明六节拍运动比四节拍运动平稳。     

Development of a linear electrostrictive servo motor

This paper presents a linear electrostrictive servo motor with high resolution and large stroke for ultra-precision motion control. High thrust force is obtained by making use of an electromagnetic clamping mechanism with force magnifying structure in the motor design. An operator alterable iterative learning control algorithm is proposed for the motion control of the motor. A prototype is designed, fabricated and tested. Experimental results show that the prototype has a mechanical resolution of 0.02 μm, yaw error less than 2 μm and maximum thrust force of 30N. Applications of the motor include producing the servo feed motions required in micro electrical discharge machining (micro-EDM) system or as a motion control device for other precision machining systems.     

尺蠖型压电直线驱动器的运动稳定性分析

为了深入研究尺蠖型压电驱动器的性能,分析了尺蠖型压电直线驱动器的工作原理,研究了直线动子对驱动器性能的影响．通过实验方法分析了钳位机构调整前后对钳住稳定性的影响．采用驱动器输出单步位移的步距失稳系数和驱动电压与输出位移拟合曲线斜率和截距偏差率的方法评价尺蠖型压电直线驱动器的运动稳定性．经实验测试发现驱动器的步距失稳系数与驱动电压关系密切,当驱动电压较高时,驱动器具有较好的步距稳定性．驱动器的驱动电压与输出位移拟合曲线斜率和截距偏差率分别为1．8％和9．07％,说明所开发的驱动器具有很好的运动稳定性．