【作者】 俞园峰；

【导师】 孙容磊；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2009， 硕士

【摘要】 气动肌肉以其类似生物的驱动特征、良好的顺应性和安全性,使它在康复医疗设备的研制中受到了极大的关注。本文以应用在上肢康复训练机器人当中的气动肌肉驱动器作为研究对象,对气动肌肉的驱动特性、气动肌肉对拉驱动的关节刚度调节和位置控制等问题进行研究和探讨,并利用ARM最新架构的CORTEX M3微控制器搭建了适用于康复训练机器人的嵌入式控制系统。由于气动肌肉压力-位移关系的非线性和时变性,研究者们很难从理论上建立一个在整个工作范围非常准确,而且适用于各种类型气动肌肉的数学模型。本文从具体的使用条件出发,建立了一种实用、简单、有效的气动肌肉驱动特性模型。单根气动肌肉只能提供拉力,而且由于编织套和内部橡胶气腔的摩擦损耗,单根气动肌肉驱动存在很大的回滞现象。因此在实际应用中,多采用气动肌肉对拉的形式驱动机器人关节。这种对拉的驱动方式借鉴的是生物骨骼肌的原理。本文以康复机器人的肘关节为模型,分析研究了肘关节刚度和位置关于气动肌肉内部气压之间的关系,提出了一种位置与刚度混合控制的策略。对气动肌肉分析研究后,本文开始着手搭建适用于康复训练机器人的嵌入式控制系统。首先分析了该控制器的功能需求,并以此为基础完成了中央处理器的选型。采用CORTEX M3微控制器作为系统的主芯片是本文的特点之一。然后分模块具体讨论嵌入式控制器的各主要功能,包括ADC模块、DAC模块、数据存储模块和以太网通信模块等。AD/DA转换是本控制器的核心功能,本文也采取多种措施尽可能提高转换精度。该控制器移植了FatFs文件系统,因此能够便利的与上位机共享文件。最后编写了基于前后台结构的系统软件,并给出了主要程序的关键代码。更多还原

【Abstract】 The pneumatic muscle actuator (PMA) is such a system having performance characteristics equal to or better than that of organic muscle. It has a very great potential in medical rehabilitation robots, because compliance and elasticity have to be considered in their actuators to get robot’s safety. In this paper we describe the model of the PMA, and discuss the way to control the stiffness and position of the joint that is actuated by an antagonistic muscle pair. After that we design an embedded controller with the latest evolution of ARM’s embedded cores– CORTEX M3, for a rehabilitation robot which is driven by the PMA.However, due to its inherent nonlinearities and time lag, this actuator suffers from poor position and force control. The researchers are very difficult to establish one accurate mathematical model in the entire operating region. Therefore, it is necessity to establish a practical, simple, and effective PMA model subject to a domain-related condition.A joint actuated by two antagonistic PMAs is common and effective, just like the principle of human arm behavior. Considering a joint that is actuated by an antagonistic muscle pair, we analyse the relationship between the stiffness, position of the joint and the pressure inside the PMAs. Later, we give a control strategy to regulate both the stiffness and position simultaneously.After that we begin to build the rehabilitation robot controller. First we analyzed the function needed, and choose the CORTEX M3 as the central processor. Then each major module is discussed specifically, including the ADC module, DAC module, data storage module and ethernet communication module and so on. The ADC/DAC is the controller’s main function, so we try all kinds of measures to increase the conversion accuracy as far as possible. A file system named FatFs is transplanted in our controller. Therefore the PC can share the file stored in the controller easily. Finally we write a control software based on the foreground-background processing, and give the key code.更多还原