Design of active orthoses for a robotic gait rehabilitation system

An active orthosis (AO) is a robotic device that assists both human gait and rehabilitation therapy. This work proposes portable AOs, one for the knee joint and another for the ankle joint. Both AOs will be used to complete a robotic system that improves gait rehabilitation. The requirements for actuator selection, the biomechanical considerations during the AO design, the finite element method, and a control approach based on electroencephalographic and surface electromyographic signals are reviewed. This work contributes to the design of AOs for users with foot drop and knee flexion impairment. However, the potential of the proposed AOs to be part of a robotic gait rehabilitation system that improves the quality of life of stroke survivors requires further investigation.     

数字式阀门电动装置力矩辨识研究

提出一种新型阀门电动装置力矩辨识方法。从异步电动机的数学模型入手,推导了静止两相直角坐标系下力矩与电压、电流关系表达式,进而实现了只须检测电动机的电压和电流即可辨识出阀门电动装置的瞬时力矩,而无须安装机械检测装置。仿真和实验结果证明了该方法的正确性和实用性,其精度完全能够满足工业生产的需要。该项研究为智能型阀门电动装置转矩机构设计提供了理论依据。     

Optimal actuator sizing and end point deformation for mobile robotic manipulators with elastic joint based on load criteria

Application of a numerical method to determine the maximum dynamic load carrying capacity (DLCC) for a robotic manipulator carrying an automobile petrol tank with joint elasticity subject to accuracy and actuator constraints is described in this paper. The maximum DLCC which can be achieved by a manipulator during a given trajectory is limited by a number of factors. The most important of which are the dynamic specification of the manipulator, the actuator limitations, and the elasticity of the joints such as reducers and servo drive system. Initially, the kinematic equations for carrying the automobile petrol tank by the robotic arm with 6 degrees of freedom (DOF) were calculated. The mechanical modeling was achieved via software programming. Dynamic modeling of the flexible joints manipulator was done simply for the three major axes. A method for determination of the dynamic load capacity with specific reference to both accuracy and actuator constraints is explained. The results obtained indicate the importance of both constraints and which constraint is more critical for accuracy and tracking.     

一种仿动物关节或腿刚度的机械腿结构设计方法

针对当前机械腿关节和动物腿关节之间、机械腿和动物腿之间的刚度曲线都有一定偏差的问题,提出了一种仿动物关节或腿刚度的机械腿结构设计方法。基于虚功原理和曲线插值法获得了动物关节或腿刚度曲线方程,并进行了Patran、Nastran、Adams联合仿真,提出了仿动物关节或腿刚度的机械腿结构设计方法及其优化方法。基于人体基本参数及人跳跃过程中腿刚度相关参数,进行了仿人腿踝关节刚度的机械腿结构实例设计和轻量化设计。仿真结果验证了该设计方法的有效性和可行性。     

一种离心开关装置的工作行为分析与研究

针对用户的需求,设计了一种在规定转速范围内能实现开关触发的装置。根据其工作原理和设计参数,按照机械动力学分析方法对所设计的产品进行仿真,研究转速变化与该装置执行端的输出位移关系。经过试验验证,理论计算结果与仿真分析的结果和实际试验值误差在6.8%以内,由此可见可以通过仿真软件ADAMS对产品的设计参数进行优化以提高其性能。     

压电作动器非对称迟滞模型的建立和参数辨识

现有的众多基于传统Bouc-Wen改进的压电陶瓷非对称迟滞模型存在参数冗余,降低了模型参数辨识的准确性,而且常用的粒子群算法(PSO)在辨识压电陶瓷非对称迟滞模型参数方面收敛慢且容易陷入局部最优值。为此,首先提出了一种归一化的非对称迟滞模型,采用两个多项式达到非对称效果,利用归一化Bouc-Wen消除参数冗余;然后采用参数和变异策略自适应的差分进化算法进行迟滞参数辨识;建立了相应的测试系统,对压电陶瓷作动器进行了实验研究。结果表明,相比于传统的Bouc-Wen模型,所提出的模型能更精确地描述压电陶瓷实际电压位移曲线,而且消除了参数的冗余,降低了参数辨识的难度。相比于粒子群算法和传统差分进化算法,自适应差分进化算法能更快更精准地找到最优参数值。     

航空发动机燃油计量装置的AMESim建模

现代航空发动机控制系统采用全权限数字电子控制,但液压机械控制装置——燃油计量装置作为一种精确控制燃油流量的执行机构,仍是控制系统必不可少的组成部分。本文基于AMESim软件建立了燃油计量装置的仿真模型,并通过物理试验验证了模型的精度。最后基于经校验的AMESim仿真模型,分析了计量装置的主要设计参数对燃油计量特性的影响,为燃油计量装置的设计提供了参考依据。     

电场活化聚合物（DE）平面弯曲致动器设计

电场活化聚合物在电场力作用下会产生大幅度的形变,可用做微型致动器的理想材料。文章探索电场活化聚合物（DE）平面弯曲致动器的设计方法,为将来更为复杂致动器的设计和应用提供理论依据;阐述了电场活化聚合物卷筒型平面弯曲致动器的工作原理,建立了力学模型,设计了致动器的结构几何参数,推导了圆柱螺旋弹簧横向弯曲刚度及其挠度、转角的计算公式。数值模拟结果表明所设计的平面弯曲致动器可以实现预期的平面弯曲运动,从而验证了这种设计方法的正确性。     

Design and performance evaluation of a 3-DOF mobile microrobot for micromanipulation

In this paper, a compact 3-DOF mobile microrobot with sub-micron resolution is presented. It has many outstanding features: it is as small as a coin ; its precision is of sub-micrometer resolution on the plane; it has an unlimited travel range; and it has simple and compact mechanisms and structures which can be realized at low cost. With the impact actuating mechanism, this system enable both fast coarse motion and highly precise fine motion with a pulse wave input voltage controlled. The 1-DOF impact actuating mechanism is modeled by taking into consideration the friction between the piezoelectric actuator and base. This modeling technique is extended to simulate the motion of the 3-DOF mobile robot. In addition, experiments are conducted to verify that the simulations accurately represent the real system. The modeling and simulation results will be used to design the model-based controller for the target system. The developed system can be used as a robotic positioning device in the micromanipulation system that determines the position of micro-sized components or particles in a small space, or assemble them in the mesoscale structure.     

模块化可重构外肢体机器人

针对单人无法独立完成的操作任务,需要额外辅助的需求,提出并研制了一种模块化、可重构的外肢体机器人,该机器人由多个结构、功能相同的基本模块单元串联组成。为了实现模块化外肢体机器人的模块连接配置与变形重构能力,分析了基本模块单元的结构、功能需求,根据需求设计了基于舵机驱动的模块单元。每个模块单元由两个楔形子模块共轴相互转动构成,形成一个转动自由度。设计了基于磁铁吸附的机械连接机构,可以实现两个模块间的快速连接与分离;提出了双排金属触点间隔错位连接方法,保证两个模块单元间实现可靠的电气系统连接。划分了双模块串联条件下4种不同的连接方位,得出了外肢体机器人的构型配置种类与串联模块个数关系。面向具有任意模块个数、不同连接方位的外肢体机器人,建立了基于虚拟转轴的模块化外肢体机器人通用正向运动学模型。对基本模块的转动能力、承载能力、快速连接能力以及外肢体机器人在焊接过程中,辅助操作人员夹持导线、递送电话等能力进行了试验,验证了所提出的新型模块化外肢体机器人的辅助能力。     

基于触摸屏交互的指套式盲文再现系统

在当今信息时代，传统的纸质盲文书籍在传播知识方面存在很多不足，逐渐无法满足视障人士的盲文阅读需求。受可穿戴装置的启发，提出了一种基于触摸屏交互的指套式盲文再现系统。根据标准盲文的结构特点、视障人士感知盲文的方式，以及指套式装置对小型化要求，设计了一种新型的盲文点执行器，并通过有限元分析对其结构和参数进行了优化。性能分析和用户实验的结果表明，提出的盲文点执行器具有刷新频率高、功耗低和体积小等优点，并能够实现在最高位和最低位的锁止操作。提出的盲文再现系统将便携的指套式装置与数据可刷新的触摸屏相结合，并利用4个压电陶瓷执行器的振动触觉反馈引导手指在触摸屏上的运动方向，为视障人士提供了一种便捷阅读盲文的新途径。     

A robotic wrist for remote ultrasound imaging

A robotic wrist has been developed for physicians to perform ultrasound imaging on patients located at remote sites. Detailed design, kinematic analysis, prototyping, and preliminary clinical tests of the wrist are reported in this paper. The wrist has certain characteristics which make it novel from mechanical point of view and with respect to its suitability for ultrasound imaging. It is a four degree-of-freedom device and uses parallel mechanisms in its configuration to provide a remote center-of-motion. All four actuators are located on the ground, and each actuator is responsible for one required motion of the ultrasound probe. The wrist has been prototyped. Successful remote ultrasound imaging of kidney and liver has been done on a few volunteers to show the applicability of the proposed device.     

适用于力反馈的圆筒式磁流变液执行器的设计

力/触觉反馈是虚拟现实交互技术中一种重要的交互形式。磁流变液执行器是最具发展潜力的力/触觉反馈装置。提出了一种适用于手指力反馈的便携式圆筒磁流变液执行器的设计方法,导出了基于B ingham塑性模型的阻力矩公式,分析了磁流变液特性和执行器结构参数对阻力矩的影响,并通过有限元分析进行优化设计,执行器的直径为31 mm,高度为38 mm,重200 g。实验测定了阻力矩和输入电流之间的关系,并采用二次多项式拟合。输入电流为0.6 A时,执行器产生的阻力矩为255 N.mm,结果表明,该执行器产生的阻力矩足以阻止手指抓取虚拟物体。     

弹性梁式构件的运动稳定性分析

结构－控制耦合系统是一种机械负载与驱动控制器相互作用的动态反馈系统。将机械系统和控制系统统一考虑,将驱动机械负载的驱动力也看成是结构－控制耦合系统的内力,则可采用处理力学上保守系统的方法使建模和分析大大简化。采用能量方法对无重力状态下弹性梁运动的相对平衡状态进行分析,得出了系统相对平衡的稳定条件。以此稳定条件作为系统运动的控制参数,有利于使弹性梁的动能转化为驱动－控制系统的电磁势能,这样一方面会加速驱动系统的制动,另一方面会迅速衰减弹性梁的振动。研究工作的结果是为弹性梁提供了一种非常简单有效的实时控制方法,该方法已在多种弹性梁试验系统上得到证实。     

Kinematic modelling of a robotic gait device for early rehabilitation of walking

Rehabilitation of walking is an essential element in the treatment of incomplete spinal cord injured (SCI) patients. During the early post injury period, patients find it challenging to practice upright walking. Simulating stepping movements in a supine posture may be easier and promote earlier rehabilitation. A robotic orthotic device for early intervention in spinal cord injury that does not require the patient to be in an upright posture has been modelled. The model comprises a two-bar mechanical system that is configured and powered to provide limb kinematics that approximate normal overground walking. The modelling work has been based on gait analysis performed on healthy subjects walking at 50 per cent, 75 per cent, and 100 per cent of normal cadence. Simulated angles of hip, knee, and ankle joints show a comparable range of motion (ROM) to the experimental walking data measured in healthy subjects. The model provides operating parameters for a prospective recumbent gait orthosis that could be used in early walking rehabilitation of incomplete SCI patients.     

Analysis of a diamond-shaped mechanical amplifier for a piezo actuator

Piezo actuators can produce high precision mechanical movement. The problem is that they can only produce very limited displacement. This paper firstly reviews the different mechanical amplifier mechanisms that increase the displacement of the piezo actuator. A mechanical analysis for one mechanism, the diamond shaped mechanical amplifier, is presented. The key design parameters of a prototype diamond amplifier for use in pneumatic valves are detailed. The results of testing the amplifier are given and compared with the theory. It is found that the displacement of the prototype amplifier does not deviate more than 7% from the theoretical value.     

集约化水产养殖监控系统设计和实现

采用嵌入式技术和LABVIEW开发了一套具有远程控制功能的集约化水产养殖监控系统。系统总体上分为3级：远程控制中心主机、现场监控基站、基于采样池的定点水质参数采集装置和机器鱼不定点水质采集装置。系统可采集的水质参数主要包括溶氧、pH、氨氮、温度和电导率等水质环境参数。主要的水产养殖执行机构有增氧机、投饵机、加热机等。该系统可以完成水质参数的实时采集和水产养殖执行机构的自动控制。     

稀土超磁致伸缩材料高速强力微位移机构的开发及动态响应特性研究

研究了稀土超磁致伸缩材料 (Tb0 .2 7Dy0 .73) Fe1 .9(商品名为 Terfenol- D)微位移机构的设计方法 ;建立了基于 Terfenol- D棒的高速强力电磁阀的动态响应特性模型 ,这一模型对基于 Terfenol- D的产品设计具有重要的参考价值 ,并用计算机对这一模型进行了仿真 ,与实验结果进行了比较、分析。     

基于加速度传感器的下肢运动信息获取方法

在智能下肢假肢的设计中,需要获取足够的下肢运动信息,而ADXL203作为一种采用集成微电子机械系统（iMEMS）技术的加速度传感器,非常适合于下肢运动姿态的测量。通过分析和研究微型加速度传感器ADXL203的原理和使用方法,设计了基于两个ADXL203传感器的下肢运动姿态识别系统,该系统能准确测试人体大腿、小腿的倾角,并通过运算得到膝关节的屈伸角度和角速度。测试结果表明,该系统非常适合于下肢运动信息的获取,并具有体积小、反应快速灵敏的优点。     

A study on the design of electromagnetic valve actuator for VVT engine

Electromagnetic valve (EMV) actuation system is a new technology for improving fuel efficiency and at the same time reducing emissions in internal combustion engines. It can provide more flexibility in valve event control compared with conventional variable valve actuation devices. The electromagnetic valve actuator must be designed by taking the operating conditions and engine geometry limits of the internal combustion engine into account. To help develop a simple design method, this paper presents a procedure for determine the basic design parameters and dimensions of the actuator from the relations of the valve dynamics, electromagnetic circuit and thermal loading condition based on the lumped method. To verify the accuracy of the lumped method analysis, experimental study is also carried out on a prototype actuator. It is found that there is a relatively good agreement between the experimental data and the results of the proposed design procedure. Through the whole speed range, the actuator maintains proper performances in valve timing and event control.