一种基于SMA的摆动式驱动器驱动原理及实验

在分析了形状记忆合金(SMA)弹簧电热驱动原理的基础上,对一种差动式关节型SMA驱动器进行了实验研究。实验结果表明:驱动电流和冷却条件对驱动器的摆动周期有很大的影响,增大电流会显著提高SMA驱动器的动作频率,但电流过大,易使SMA失去形状记忆功能,所以,电流应控制在一定的范围之内。驱动器的动作频率还受到冷却速度的制约,加快冷却速度也会提高驱动器的动作频率。     

胶囊内窥镜机器人微驱动仿真研究

提出了一种采用形状记忆合金螺旋弹簧作为驱动源的新型胶囊内窥镜机器人.介绍了微驱动机构及机器人运动原理.在形状记忆合金(SMA)微驱动器热学模型、相变模型理论的基础上,进行了仿真实验.仿真结果与实际加热过程和冷却过程基本吻合,为设计胶囊内窥镜机器人驱动器控制系统提供了依据.     

基于SMA的关节驱动器的力学分析及控制

分析了一种用于水下微小型仿生机器人的形状记忆合金(SMA)关节驱动器的力学特性,并通过模糊控制的方法对其进行了实验研究。结果表明:对于物理特性呈非线性、温度滞后、时变和受温度影响很大的SMA驱动器来说,采用模糊控制的方法,能够使驱动器稳定、平滑的工作,尽管产生了轻微的超调现象,但收到了令人较为满意的效果。因此,将模糊控制方法应用于SMA驱动器的控制有一定的理论意义和应用价值。     

基于蚯蚓原理的多节蠕动机器人

介绍了多节蠕动机器人的机体构造和运动原理，建立了机器人运动模型并进行了分析. 阐述了该机器人系统的控制组成和软件设计. 讨论了机器人在不同倾角橡胶管道内的驱动性能试验.进行了机器人温度试验及转弯性能试验.结果表明：该微小型机器人运行可靠、平稳，控制方便，有一定的爬坡能力；连续工作时机器人温度不超过35℃；可通过大于36mm的弯曲半径.该研究为非结构环境狭小空间及人体消化道探察机器人的研制奠定了基础．     

用于呼吸道直接监测的柔性微机器人系统

根据人体呼吸系统的结构及生理特性,基于蠕动运动原理设计了适于人体气管及左右主支气管内自由移动的微机器人系统．该机器人系统采用三自由度空气压橡胶驱动器驱动的柔性移动机构．介绍了机器人机体的构造和运动原理,建立了机器人系统驱动力学模型并做了相应分析．在猪气管中进行了初步实验,在机械通气情况下监测了气管末端的压力和温度参数．初步的研究结果表明,该柔性驱动机器人系统可用于直接动态监测机械通气过程中的呼吸参数．     

一种新型球形机器人虚拟样机的设计及运动仿真

提出了一种采用双齿轮齿条传动机构的新型球形机器人设计方案,该方案在球形机器人同一直径方向上安装两组齿轮齿条传动机构作为内部驱动装置,论文详细介绍了该球形机器人的机械结构,并通过受力分析对其直线运动和转弯运动的运动原理进行了理论分析。联合使用SOLIDWORKS和ADAMS,建立了球形机器人的虚拟样机并进行运动仿真。受力分析和运动仿真结果验证了该球形机器人结构的可行性,为物理样机后期制作提供依据。     

仿蚯蚓蠕动微机器人牵引与运动控制

为进入人体腔道开展作业,开发了一种直径6mm的仿蚯蚓多关节蠕动微机器人样机．机器人使用十字万向节连接直线驱动器,在弯曲腔道中能自适应改变自身姿态．基于Preisach模型和偏转模型,提出了形状记忆合金偏转机构的前馈控制方案,头舱控制最大偏转误差为2.6°．基于新型蠕动原理,建立了牵引模型,给出了有效驱动的条件．对机器人的牵引力、运动速度、在不同摩擦系数介质表面上的运动能力、头舱姿态进行了试验．结果表明,机器人的爬坡能力依赖于机器人和运动表面间的摩擦系数,新型蠕动原理能提供较大的牵引力,合适的驱动频率下可以得到最大的运动速度．     

SMA微驱动器的设计方法

前言 微驱动器是微型机器人中的重要组成部分。形状记忆合金(SMA)用于微驱动器是一种极好选择。SMA体积越小,功重比越大;采用SMA驱动后可省略传动机构,使结构大为简化;同时可以实现精确控制。本文主要介绍SMA微驱动器的设计方法。     

一种仿虎甲幼虫的多驱动器软体机器人的设计与制造

设计和制造了一种多驱动器软体机器人来模拟虎甲幼虫的爬行、转向和咬合运动．其中,软体机器人尾部采用多气囊式软体驱动器,实现了向前运动;软体机器人颈部采用纤维增强弯曲致动器,实现了转向运动;软体机器人头部采用形状记忆合金（SMA）弹簧驱动,实现了咬合运动．最后,模拟虎甲幼虫爬行捕捉小红果进行了实验,结果证明该软体机器人的多驱动器设计可以模拟虎甲幼虫进行复杂运动．     

柔性蠕动管道机器人的牵引力及软轴结构稳定性分析

为解决柔性蠕动管道机器人的运动控制问题,提高机器人管内行走效率,对一种具有导向头和刹车轮结构的柔性蠕动管道机器人进行了深入分析和研究.通过对机器人进行管内受力分析,建立起机器人的牵引力模型;为提高机器人在不同管道环境中的运动性能,对软轴结构的运动稳定性进行了分析,提出了机器人蠕动运动失稳的概念,并采用长柱体的稳定性理论进行分析,推导出机器人在直管和L型管道中的临界失稳条件,为柔性蠕动管道机器人步距规划提供了理论依据.搭建管道实验环境进行机器人的牵引力和行走实验,测试值与理论分析基本一致,说明柔性蠕动管道机器人具有优良的牵引能力,行走过程中的运动失稳现象也验证了软轴临界失稳理论的正确性.     

SMA驱动的微型平面关节机器人的研究

近年来，利用形状记忆合金（ＳＭＡ）的形状记忆效应原理制作的驱动器已在机器人领域中得到应用，ＳＭＡ驱动器以其重量轻、结构紧凑、易控制等优点，大大推动了微型机器人的发展．本课题使用所研制的推挽式直线位移型和旋转关节型ＳＭＡ驱动器代替传统的伺服驱动系统，研制了一台三自由度（两个旋转自由度和一个直线自由度）且带末端夹持器的微型平面关节机器人．本文将介绍该机器人的结构设计，控制系统及其软件设计．     

An earthworm-like micro robot using shape memory alloy actuator

A novel bio-mimetic micro robot with wireless control and wireless power supply using shape memory alloy (SMA) actuator is developed. There have been many kinds of mobile micro robot using the micro actuators such as ionic polymer metal composite (IPMC), micro motors and piezo actuators. These actuators generally require electric cable for power supply, which might highly influence the mobility of the micro robot. Therefore, a perfect wireless micro robot comprising telemetry and batteries is realized using only one SMA spring actuator and one silicone bellow. The SMA actuator and bellow play a role in contraction and extension of an earthworm muscle respectively. Based on theoretical analysis, specifications of a SMA actuator and a bellow are properly selected. For temporal stopping, setae of earthworm mimicked claws are employed. On the issue of control, the proposed robot is controlled according to On/Off signal via wireless communication. The operation is customized through tuning of on-/off-time of an actuator and using different type batteries such as a lithium, silver oxide and alkaline battery. After the design and experiment, we find out that the earthworm-like micro robot without wired power supply and control can move freely without limitation of working space and be fabricated easily.     

Development of a shape memory alloy actuator. Improvement of output performance by the introduction of a σ-mechanism

The driving-force-generating principle of an actuator made of shape memory alloy (SMA) is based on the thermal elastic martensitic transformation, a kind of elastic phenomenon. As a result, conventional SMA actuators which use a circular pulley have tended to exhibit undesirable characteristics such as the maximum generable torque being changed depending on the rotating angle when the robot joint was driven by rotating motion transformed from expansion/contraction of the SMA, so that the servo system to support the torque under a certain load could not have an operable range wide enough for practical application. This paper intends to clarify these problems of SMA actuators and proposes a new joint mechanism using a σ-shaped non-circular pulley, called the σ-mechanism, for joint linkage to overcome the problems. This design enables the maximum generated torque to be kept uniform at all times by reducing the torque-arm-length in inverse proportion when the SMA tension increases corresponding to the rotating angle of the joint. Subsequently, a specifically designing algorithm for the proposed σ-mechanism is discussed. The validity of the new mechanism is demonstrated by an experimental model using an SMA actuator with a σpulley.     

Design of an shape memory alloy-actuated biomimetic mobile robot with the jumping gait

This paper reports the design, simulation, analysis, and experiments of mesoscale fourlegged robots that can locomote by a jumping gait using only shape memory alloy (SMA) wires as actuators. Through studies of the structure and function of leg muscle groups in vertebrates’ lower musculoskeletal system, three types of muscles are selected for robot leg design, and each muscle is then replaced by an SMA wire in the robot model. Two types of robot models are proposed and analyzed using three sets of computer simulation. It can be concluded from the simulation that the sequence of SMA muscle activation, activation arrangement of the rear and the front legs, and the foot length are primary factors determining the jumping performance. It is observed that when the robot has three degrees of freedom for each leg and a foot length of 40 mm, the maximum jumping height is approximately 120% of the robot’s height and the maximum distance per jump is about 35% of its length. In addition, two robot prototypes are presented based on the design models and experimental results. The simulation and experimental results are found to show good agreement. The overall results show that the proposed robot design and SMA actuation method are feasible for all SMA-driven jumping robots.     

Architecture design of a multiaxis cellular actuator array using segmented binary control of shape memory alloy

A new approach to artificial muscle actuator design is presented, and is implemented using shape memory alloys (SMA). An array of SMA actuators is segmented into many independently controlled, spatially discrete volumes, each contributing a small displacement to create a large motion. The segmented cellular architecture of SMA wires is extended to a multiaxis actuator array by arranging the segments in a two-dimensional (2-D) array. The multiaxis control is streamlined and coordinated using a 2-D segmentation method in order to activate multiple links of a robot mechanism in a coordinated manner. The basic principle of segmented binary control (SBC) is first presented, followed by multiaxis segmentation theory and a design procedure. The method is applied to a five-fingered robotic hand capable of taking a variety of postures. A 10-axis SMA actuator array is built, and SBC is implemented using Peltier-effect thermoelectric devices for selective local heating and cooling. Experiments demonstrate the feasibility and effectiveness of the new method.     

仿生“蚯蚓”机器人的SMA 执行器实现

虽然从生物学角度来说,蚯蚓的波浪式运动机制已经相当清楚,但在小尺寸下人工蚯蚓的实现仍然是极具挑战性的工作.采用记忆合金材料(SMA),设计实现了用于仿生蚯蚓机器人的执行器,并通过该执行器的动作循环模仿,实现了蚯蚓的波浪式运动.实现的人工蚯蚓共有四单元,每一单元都有可独立驱动的执行器.执行器由一根或三根SMA弹簧构成,其波动式运动的最高频率为0.6 Hz.每一单元人工蚯蚓,都被覆特定形状的软硅胶皮,该硅胶皮提供了SMA执行器的对抗力,同时也是安装微型腿的平台,从而进一步提高了人工蚯蚓的运动效率.初步的测试显示该执行器工作有效,人工蚯蚓的运动速度可达2.5mm/s,与真实的蚯蚓运动速度相近.     

Modeling of pneumatic muscle with shape memory alloy and braided sleeve

Pneumatic muscle (PM) of flexible actuators used in bionic robot is an active area of recent research. A novel PM with shape memory alloy (SMA) braided sleeve is proposed in this paper, and SMA is used to improve PM working characteristics. Based on the principle of virtual work, output force model of PM and relationship with braided wire inner-stress are established, and analysis of PM deformation has shown that braided wire length is the key factor of output force characteristic. Based on the crystal structure transitions, the relationship of temperature with wire shrinkage is derived. Then, the synthetic dynamics of novel PM is established. A physical prototype of PM with SMA braided sleeve is developed, and test platform that is built for the experiment. Experiment and simulation test of static isometric-length, static isobaric-pressure, and dynamic characteristics are done. The experimental results are compared with the simulation of theoretical model. Moreover, based on experiment, model of output force was improved by adding a correction factor to deal with the elastic force of rubber tube. The results analysis demonstrates that the established models are correct, and SMA wires can reinforce PM and make PM working characteristics adjustable. PM proposed in this paper has greater output force and is beneficial to achieve more accurate control that is useful for manipulating fragile things.     

Micro actuators on the basis of thin SMA foils

Three innovative micro actuator concepts on the basis of the differential SMA principle are presented in this paper: a high adaptive multi-actuator system, which is driven by numerous identical single actuators connected in parallel and in series, a micro gripper for handling and assembling of complex hybrid micro systems and a micro actuator system in medical tools for the percutaneous resection of aortic valves. The SMA material is used in the form of 50 μm thin NiTi foils because of their well-defined properties and high strength. In order to integrate them into micro systems, different manufacturing methods have been applied and improved at the Institute for Microtechnology. Laser cutting and wet chemical etching are used for example to microstructure the actuator elements. Different methods for electrical and mechanical connections of the actuators are employed like soldering by the use of an additional gold layer. A batch fabrication process of SMA actuators is realized by embedding NiTi foil elements into SU-8 structures. To optimize the design of SMA actuator elements according to its application different simulation procedures are used.     

仿生鱼鳍中形状记忆合金驱动器的水下变形精度分析

简要介绍了仿生鱼鳍的基本机构和工作原理．为了提高形状记忆合金仿生鱼鳍的变形精度,理论计算了作为鱼鳍驱动器的形状记忆合金薄板对端部的水下变形误差．给出了形状记忆合金薄板表面的流体无量纲阻力系数随时间的变化关系,同时给出了某一时刻薄板表面及其周边的压力分布和薄板尾迹中的卡门涡街形态．最后,通过实验验证了理论推导的正确性．     

移动机器人导航模型的设计方法

本文针对自主式移动机器人的系统结构，利用Ｐｅｔｒｉ网建立了同步和异步两咱流水线模型，并分析了各自的特点和性能同步流水线模型适用于功能模块工作时间大致相等且稳定的场合能发挥精确、安全的优势；异步流水线模型则具有更快的处理速度。