Antagonistic muscle-like actuator and its application to multi-d.o.f. forearm prosthesis

It is first clarified through simulational analysis that co-activation between agonist an muscle and its antagonist both having nonlinear elasticity is indispensable for the stiffness adjustment on an articulator movement. An antagonistic muscle-like actuator (AMA) is then proposed as an approach of imitating a skeleto-muscular articulation system. The AMA has two nonlinear springs which drive one joint antagonistically and provides the joint with the feasibility of stiffness adjustment. The development of the forearm prosthesis which has 6 d.o.f. is developed as an application of the AMA. Two d.o.f. for the wrist and 4 d.o.f. for the two fingers are driven by only one DC motor and one stepping motor for exchanging the driving mode. The whole mechanism is designed as almost the same volume as an adult's forearm. A shape fit mechanism for the finger is proposed, by which the three joints of one finger automatically adjust their angle according to the shape of the object to be grasped.     

Development of a pneumatic soft actuator with pleated inflatable structures

Many soft actuators have been studied for use in robots that come into contact with humans, including communication, entertainment, and medical/health care robots. One reason for this is that soft robots are expected to exhibit intrinsic safety in case an accident occurs. This paper proposes a plastic-film pneumatic actuator with a pleated structure that do not undergo the elastic deformation typical of rubber materials. By utilizing thin plastic films, the mass of an actuator can be significantly reduced, even if the actuators are the same size as a human arm. If the mass of the actuator is reduced, the kinetic energy when contacts with humans mechanically can be reduced considerably without reducing the working speed. More specifically, we propose a pleated structure made of plastic to achieve structural deformation generated from a two-dimensional pleated film. The pleated structure easily generates various bending motions. In this paper, a design method for determining the shape parameters of the pleated actuator structure using approximate models with considering measurement results of generating force is presented. We evaluated the adequacy of our approach in experiments using sample actuators. Furthermore, we show the constraints required to determine the necessary parameters. Thus, this paper provides an easy method for designing a lightweight and flexible plastic-film actuator.     

Application of Piezoelectric Manipulator in Fine Manipulation

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双圆锥静压支承应用在电液伺服作动器中的研究

通过圆锥静压支承流体力学建模和无因次特征参数优化选择的研究，对该结构形式的抗侧向力，临界空穴速度、泄漏量等特进行了计算，并作了推证和合理简化。文中还通过试验和工程实践的验证表明，采用双圆锥静压支承的伺服作动器可使被控伺服系统静动态特性得到满意的结果。     

液压舵机伺服系统的专家PID控制

为了更好地分析与优化液压舵机的控制性能,根据控制理论建立了液压舵机伺服系统的数学模型;针对采用常规控制方法液压舵机系统响应速度慢、抗干扰能力差等问题,在对专家经验进行总结并获取5条控制规则后,设计了专家PID控制器;在单位阶跃信号的作用下,运用Matlab/Simulink对该液压舵机系统进行仿真;仿真结果表明,与常规PID控制、P控制相比,专家PID控制使系统调节时间缩短了0.104s,缩减幅度达71%,受到干扰后再次稳定的时间缩短了0.034s,有效地提高了快速性和抗干扰性,获得了良好的控制效果。     

三关节式软体驱动器的设计及其弯曲性能分析

针对传统的刚性机器人在辅助人体康复训练时存在康复效率低、易造成人体二次损伤等问题,依据人体手指结构及其关节的运动范围,提出了一种由硅胶材料制成的三关节式软体驱动器。首先,根据 Yeoh 超弹性材料本构模型和虚功原理,在理想条件下建立了软体驱动器气囊的弯曲角度与输入气压之间的非线性数学关系,进而研究在一定气压下驱动器不同结构参数对其弯曲性能的影响;接着,通过有限元模型仿真得出了驱动器壁厚、底层厚度和腔室外直径对驱动器弯曲性能影响的显著性排序;最后,通过 3D 打印及模塑成型工艺,制作了三关节式软体驱动器,搭建了软体驱动器弯曲性能测试平台以测试其弯曲性能。结果表明：随着输入气压的增大,软体驱动器弯曲角度的理论计算结果与实验结果的相对误差逐渐减小,当气压高于20 kPa时,其最小相对误差为1.48%;当腔室内部气压为50 kPa时,软体驱动器输出力为0.45 N。可将软体驱动器应用于人机交互的辅助康复领域,后期有望应用于农业和生物医学领域。     

超磁致伸缩致动器动态特性分析与实验研究

基于超磁致伸缩材料磁滞非线性,结合其致动器结构,推导了致动器的动态应变模型.为了验证模型的准确性,进行了致动器动态特性测试,测试结果和理论仿真结果基本一致,为致动器的实际使用打下了基础.     

Stable Fault-tolerance Control for a Class of Networked Control Systems

In this paper, we use the matrix measure technique to study stable fault-tolerance control of networked control systems. State feedback networked control systems with the network-induced delay, parameter uncertainties, sensor failures and actuator failures are considered. State feedback gain K is designed for any invariant delay T, and some theorems and sufficient conditions for stable fault-tolerance control are given. Example is presented to illustrate the effectiveness of these theorems.     

一种用于流动控制的MEMS微致动器研究

设计制作了一种基于M EM S技术的微气泡型致动器,并对前缘布置有微致动器的三角翼进行了数值模拟,结果表明:微致动器可以改变三角翼前缘的旋涡流状态,扰动边界层分离,改变三角翼前缘分离涡的位置,合理布置微致动器可以获得一定的俯仰、滚转和偏航力矩,利用微致动器成功进行分离涡流控制。     

一维压电式微定位机构的设计研究

针对精密工作台高速、低精度的矛盾,以柔性铰链为导向元件、压电陶瓷为驱动器,研究、设计了一种一维高分辨率压电式微定位机构。由于精密工作台高速运动产生的运动惯量较大,欲实现亚微米级的定位精度是很困难的,因而在精密工作台运行到位后,由微定位机构对检测装置所检测出的定位误差进行补偿,以提高工作台的定位精度;由于压电陶瓷微位移器件输出位移过小,因此提出了一种单自由度对称式柔性铰链放大机构来提高微定位行程。给出了机构的动力学模型,并结合光栅尺检测装置,设计并研制了数字闭环定位控制系统,对微定位机构的定位特性进行了测试。实测结果表明,此微定位系统可实现高分辨率、长行程定位,定位分辨率达0.01μm。