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为了满足肠道机器人在肠道中运动和驻留的要求,设计了一种大变径比的新型扩张机构。该机构通过采用双层叠腿式设计,增大了与肠道的接触面积,最大扩张半径达到24.5mm,变径比增加到3.27。为了进一步研究该扩张机构的性能,建立了扩张臂的数学模型,对扩张臂的力学与运动学特性进行了理论分析。然后通过有限元分析,对扩张臂运动过程进行了动力学仿真,研究了不同扩张半径下,扩张臂的应力分布和变化趋势,基于有限元分析结果,对扩张臂进行了优化设计,优化后的等效应力最大值比优化前减小了12.89%。之后通过ADAMS对扩张臂进行运动学仿真,以验证其运动学模型的准确性。最后搭建了力学性能实验台,对其扩张力进行了测试,以验证其力学模型的准确性。实验结果显示:实验值与理论值的变化趋势基本一致,而且实验值小于理论值;机构扩张初始阶段误差较大,扩张半径为7.5 mm时,实验值仅为理论值的14.30%;之后误差急剧减小并趋于稳定,扩张半径为10~23mm时,实验值平均为理论值的73.64%;扩张臂1、2、3的实际扩张半径分别为24.5、24和23mm。结果显示本文设计的肠道扩张机构基本满足肠道安全性和大变径比的设计要求,而且结构优化效果明显。 相似文献
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胶囊内窥镜在肠道中的钳位 总被引:1,自引:1,他引:0
由于胶囊内窥镜的有效钳位是实现其在肠道中有效驻停及运动的重要因素,本文研究并设计了胶囊内窥镜的钳位机构.首先,基于对摩擦力和肠道形变的分析,讨论了影响钳位力的因素.考虑肠道安全性,设计了阿基米德螺线腿机构.然后,通过构建离体肠道测试平台,测试不同直径、宽度、纹理及形状的样本在肠道内的钳位特性;分析实验结果,并建立了可定性描述钳位力的方程.最后,基于电流反馈实现钳位机构的安全控制;通过离体实验测试了钳位机构运动性能,并验证了钳位机构的安全性和可行性.实验结果显示,优化后的螺线腿钳位机构的钳位力达1.486 N;可较好地适应肠道的生理环境,满足扩展肠道、安全钳位的要求. 相似文献
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医用微型机器人蠕动肠道中的驱动力计算及实验研究 总被引:6,自引:2,他引:6
提出了一种新型的可进入人体内腔和微型机器人驱动机构。此种微型机器人能够在充满液体的弯曲的人体肠道内运行。当机器人在充满液体的微型管道内运行时,在其周围会自动形成一层液体动压润滑膜,此润滑膜能避免机器人与管道壁发生直接接触。结合人体肠道的蠕动方程和N-S方程利用有限元分析计算了此种微型机器人在蠕动肠道中的驱动力和运行速度,进行了机器人的运行实验,结果表明,机器人能以较快速度在肠道内悬浮运行。 相似文献
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肠道微机器人柔性运动系统 总被引:1,自引:1,他引:0
提出一种适用于肠道微机器人的柔性运动系统来提高肠道机器人微创诊断的主动运动能力.柔性运动系统采用尺蠖型运动方式,由柔性运动机构和柔性驱动机构组成.柔性运动机构包括径向气囊软足和轴向伸缩推杆,并用万向节连接微机器人前后腔体从而提高运动柔性;柔性驱动机构利用尼龙线绳牵引波纹管泵驱动气囊软足和伸缩推杆激励微机器人伸缩.微机器人样机直径为12.2 mm,长度为78 mm,质量为14.8g,最大径向钳位外径为20.2 mm,最大轴向行程为16.4 mm.实验结果表明,柔性驱动机构可以为波纹管泵和伸缩推杆分别提供最大为0.67N和0.65 N的驱动力;微机器人样机能够在不同倾斜角度的刚性有机玻璃管中运动,在水平和竖直管道中的平均运行速度为0.38 mm/s和0.25 mm/s;能通过最小曲率半径为49.3 mm的塑料软管,在离体肠道中也能实现有效运动.本柔性运动系统为肠道微机器人提供了一种安全有效的自主运动方案. 相似文献
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设计了一种能自适应吸附不同直径管道的非接触变磁隙式攀爬机器人。采用矢量磁位法和有限元法建立了吸附机构的磁场分布模型和磁吸附力模型。基于空间力系统的平衡方程建立了机器人的力学模型,得出爬壁机器人需要的最小磁吸附力。基于磁场和磁吸附力的理论模型与Maxwell仿真,通过离散组合法得到了最优磁铁宽度和磁吸附力。通过不同磁场和磁吸附力的对比计算,在最优磁铁宽度为80 mm时,得出近似圆弧机构单位体积的磁吸附力为0.0078 N/mm3,大于矩形磁铁单位体积的磁吸附力0.0047 N/mm3,它产生的磁吸附力满足单个机构所需的最小磁吸附力2100 N的负载要求。最后,通过实验获得了磁吸附机构的磁吸附力特性,证明了磁吸附机构优化设计的可行性。 相似文献
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《制造业自动化》2017,(7)
针对农林业领域复杂的树木检测环境,设计一种仿蠕虫爬行负重爬树机器人。通过提升机构的伸缩运动改变自身形态,以实现对树干的竖直攀爬运动;通过夹紧机构中推杆的伸缩,控制各夹紧机构对树干的夹持力;同时,对机器人在不同直径或倾斜度的树木攀爬时进行静力学分析,使机器人可根据得到的夹紧力范围自适应调节,提高机器人攀爬的稳定性和运动的灵活性。最后,通过ANSYS软件对机器人的机械结构进行有限元分析验证。结果表明,所设计的负重机器人携带检测设备爬树时,机器人总变形量最大值为5.24mm,符合结构安全性要求,且承载最大应力为100Mpa,符合机器人所选材料安全性要求,进而验证了机构设计的合理性。 相似文献
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管道机器人适应不同管径的三种调节机构的比较 总被引:10,自引:0,他引:10
为了使管道机器人能够适应管径为400~650mm的管道,介绍了3种适应不同管径的常用调节机构.分析了每种调节机构的力学特性,给出了计算结果,比较研究了各种调节机构的优缺点.针对工程需要,选用了滚珠丝杠螺母副调节机构,滚珠丝杠上的筒式压力传感器保证驱动轮和管道内壁间的压力始终处于稳定的范围,使管道机器人具有充裕并且稳定的牵引力,牵引力的实验表明该调节机构具有1404N的牵引力输出.该调节机构能很好地适应管径为400~650mm的管道. 相似文献
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A model is first built for predicting the velocity-dependent frictional resistance of a capsule robot that moves inside the intestine in the paper. The capsule robot plays a more and more important role in checking diseases in the intestine. This study aims to optimize the locomotion mechanism and the control strategy of the capsule robot. The model consists of three parts: environmental resistance, viscous friction, and Coulomb friction. Environmental resistance is induced by the stress due to the viscoelastic deformation of the intestinal wall. Viscous friction is analyzed according to the apparent viscosity of intestinal mucus. Coulomb friction is a product of the local contact pressure and the Coulomb friction coefficient. In order to analyze the effects of the intestinal deformation, a five-element model is used to describe the stress relaxation of the intestinal material. Experimental investigation is used to identify the model parameters with homemade physical simulation measurement system and fixtures. Finally, the model??s validity is verified by experimental results. It is shown that the model predicting results can fit the experimental results well when the moving velocity of the capsule is lower than 20?mm/s. The R 2 of these two sets of data is 0.8769. But at a higher velocity, there are significant differences between the two results and the R 2 declines to 0.1666. The friction model is expected to be useful in the development of the medical equipment in the intestine and the study of biomechanics of the intestine. 相似文献
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Sukho Park Hyunjun Park Sungjin Park Byungkyu Kim 《Journal of Mechanical Science and Technology》2006,20(7):1012-1018
Diagnosis and treatment using the conventional flexible endoscope in gastro-intestinal tract are very common since advanced
and instrumented endoscopes allow diagnosis and treatment by introducing the human body through natural orifices. However,
the operation of endoscope is very labor intensive work and gives patients some pains. As an alternative, therefore, the capsule
endoscope is developed for the diagnosis of digestive organs. Although the capsule endoscope has conveniences for diagnosis,
it is passively moved by the peristaltic waves of gastro-intestinal tract and thus has some limitations for doctor to get
the image of the organ and to diagnose more thoroughly. As a solution of these problems, various locomotive mechanisms for
capsule endoscopes are introduced. In our proposed mechanism, the capsule-type microrobot has synchronized multiple legs that
are actuated by a linear actuator and two mobile cylinders inside of the capsule. For the feasibility test of the proposed
microrobot, a series of in-vitro experiments using small intestine without incision were carried out. From the experimental
results, our proposed microrobot can advance along the 3D curved and sloped path with the velocity of about 3.29–6.26 mm/sec
and 35.1–66.7% of theoretical velocity. Finally, the proposed locomotive mechanism can be not only applicable to micro capsule
endoscopes but also effective to advance inside of gastro-intestinal tract. 相似文献
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针对串联四足机器人行走惯量大,自重/载重比大的问题,提出一种新型串并混联四足步行机器人,并对该机器人的串并混联腿进行运动学分析。该机器人由一个运载平台和四条结构相同的串并混联腿组成,每条腿均由髋关节、大腿、小腿顺次连接构成,其中髋关节为3-RRR并联机构。以能耗最小姿态为最优姿态,基于矢量法求解了该串并混联腿的运动学正解和反解,利用MATLAB和ADAMS软件验证了正解和反解的正确性;基于矢量法和微分变换法求出了该混联腿的速度雅克比矩阵和加速度矩阵,分析了其奇异性,并利用MATLAB软件绘制出该腿的工作空间。结果表明:该腿在髋关节连杆直径d=22mm,大腿杆件直径D=50mm,膝关节转角θ4∈[105°,155°]时,工作空间呈球冠形,最大内接圆半径R=400mm,高度为H∈[500mm,900mm]。本研究对该新型串并混联四足步行机器人的刚度分析、动态性能、机构优化设计和系统控制等的进一步研究具有重要意义。 相似文献
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An in-pipe moving mechanism based on design parametric study of dynamic characteristics of clamping or moving module comprising
shape memory alloy (SMA) spring actuators has been fabricated and evaluated under in-pipe condition. Conventional in-pipe
moving mechanisms for pipe inspection, driven by electromagnetic motors, have large volume and mass. The SMA actuator can
be an alternative for a small-sized in-pipe moving mechanism due to its great power-to-weight ratio and simple structure.
Therefore, spring type SMA actuators are selected to fabricate an inchworm-like moving mechanism that consists of clamping
and moving modules. For selection of proper operating type (a bias type or a differential type) for clamping module and moving
module, displacements and dynamic characteristics of each operating type have been investigated. Based on experimental results,
we decide some design parameters such as wire diameters, spring diameters and the numbers of turns of SMA spring actuators
and fabricate the in-pipe moving mechanism according to the designed results. A moving speed of 34 mm/min and traction force
of 0.4 N have been obtained from the driving experiment in a pipe with the diameter of 39 mm. 相似文献