基于LinuxCNC控制器的六自由度并联机构人机交互系统设计

发布时间：2018-03-26 22:21

本文选题：六自由度并联机构　切入点：LinuxCNC控制器　出处：《江苏科技大学》2014年硕士论文

【摘要】：当前，基于Stewart平台的六自由度并联机构具有刚度大、重量轻、结构紧凑等优点，已经在空间机器人、并联数控机床等各尖端行业得到了广泛的应用。六自由度并联机构如果要完成某种特定的空间位姿或运动轨迹，实现机械系统设计的目的和任务，必须在控制器的控制作用下，通过进给驱动系统才能够实现。并联机构的开放性和多样性决定了与其配套的控制器也应该是开放的，国内外已经构建了开放式控制系统的标准协议和体系框架，但目前尚没有完全标准化和系列化。传统的控制器功能封闭、价格昂贵、配套硬件设备复杂，很难获得。但运行在开源Ubutu10.04实时操作系统环境下的LinuxCNC控制器是开源的，可从其网站上免费下载使用。本论文是基于LinuxCNC控制器，对六自由度并联机构进行研究，利用使用广泛的跨平台高级语言Python作为开发工具，开发设计了三维运动模型和虚拟控制面板，选用了运动控制卡、步进电机、滚珠丝杠等驱动装置，从而构建基于LinuxCNC控制器下的六自由度并联机构人机交互系统。其控制命令可以通过使用UG数控模块生成的标准数控代码来执行。本文主要研究内容如下：第一、分析并联机构的命名方法，，计算基于Stewart平台的6-UPS型并联机构的自由度数。对并联机构的正解和逆解算法进行分析，使用Python科学计算库函数编制六自由度并联机构逆解算法，并根据特例对杆长变化曲线进行仿真。第二、对LinuxCNC软件构架、通讯机制、运动控制系统进行详细分析，其模块化的设计思想和遵循开源协议的精神，使得通过调用合适的模块就能配置成实现特定功能的控制器。详细解析硬件抽象层及其halcmd语言，该语言是调用、配置LinuxCNC各模块、开发三维动态模型、建立虚拟控制面板、连接软硬件之间的信号和引脚的专用工具。第三、对比分析LinuxCNC控制器本身自带的两种界面模式Tkemc和AXIS，选择基于Python语言开发的AXIS界面模式。使用PyOpenGL（Python+OpenGL）语言构建了三维动态模型，通过硬件抽象层halcmd语言建立模块之间的连接，使得在AXIS界面模式下，通过输入数控代码，利用LinuxCNC控制器，可以直观形象地观察到六自由度并联机构平台运动轨迹及杆长的变化位姿。第四、在LinuxCNC控制器的AXIS界面模式下进行虚拟面板自定义设计。使用PyVCP（Python+XML）语言构建了虚拟控制面板，通过硬件抽象层halcmd语言建立模块之间的连接，使得硬件设备接通电源后，就可以在虚拟控制面板上直观地观察到硬件运行状况。分析使用GladeVCP进行触摸屏控制界面设计的方法步骤。第五、结合前面章节实现了的三维动态模型及虚拟控制面板，通过对LinuxCNC控制器进行软硬件配置，选取步进电机、驱动系统，设计了基于LinuxCNC控制器下的六自由度并联机构人机交互系统。
[Abstract]:At present, the six-degree-of-freedom parallel mechanism based on Stewart platform has many advantages, such as high stiffness, light weight, compact structure and so on. Parallel control machine tools and other cutting edge industries have been widely used. If a 6-DOF parallel mechanism is to complete a certain spatial pose or motion trajectory, and to achieve the purpose and task of mechanical system design, it must be controlled by the controller. The opening and diversity of parallel mechanism decide that the corresponding controller should be open, and the standard protocol and framework of open control system have been constructed at home and abroad. But at present, it is not completely standardized and serialized. The traditional controller is closed in function, expensive in price, complex in hardware and difficult to obtain. However, the LinuxCNC controller running in open source Ubutu10.04 real-time operating system is open source. It can be downloaded free of charge from its website. This paper is based on the LinuxCNC controller, studies the six-degree-of-freedom parallel mechanism, uses the widely used cross-platform high-level language Python as the development tool, develops and designs the three-dimensional motion model and the virtual control panel, selects the motion control card. Stepping motor, ball screw and other driving devices, In order to construct the human-computer interaction system of 6-DOF parallel mechanism based on LinuxCNC controller, the control command can be executed by using the standard NC code generated by UG numerical control module. The main contents of this paper are as follows:. First, the naming method of parallel mechanism is analyzed, and the number of degrees of freedom of 6-UPS parallel mechanism based on Stewart platform is calculated. The forward and inverse solutions of parallel mechanism are analyzed. The inverse solution algorithm of a 6-DOF parallel mechanism is developed by using the Python scientific calculation library function, and the variation curve of the rod length is simulated according to the special case. Secondly, the software architecture, communication mechanism and motion control system of LinuxCNC are analyzed in detail. The modular design idea and the spirit of open source protocol are followed. The hardware abstraction layer and its halcmd language are analyzed in detail. The language is to call, configure LinuxCNC modules, develop 3D dynamic model, and establish virtual control panel. A dedicated tool for connecting hardware and software between signals and pins. Thirdly, comparing and analyzing the two interface modes of LinuxCNC controller, Tkemc and ax, we choose the AXIS interface mode based on Python language, and construct the 3D dynamic model with PyOpenGL(Python OpenGL language. Through the hardware abstraction layer halcmd language to establish the connection between the modules, make use of the LinuxCNC controller in the AXIS interface mode, through the input numerical control code, The kinematic trajectory and pole length of the parallel mechanism with six degrees of freedom can be observed intuitively and vividly. Fourthly, the design of virtual panel in AXIS interface mode of LinuxCNC controller is carried out. The virtual control panel is constructed by using PyVCP(Python language. The connection between modules is established by halcmd language of hardware abstract layer, which makes the hardware device power on. The hardware running condition can be observed intuitively on the virtual control panel, and the method and steps of using GladeVCP to design the touch screen control interface are analyzed. Fifthly, combined with the 3D dynamic model and virtual control panel realized in the previous chapters, through the hardware and software configuration of the LinuxCNC controller, the stepper motor is selected to drive the system. A 6 DOF parallel mechanism man-machine interaction system based on LinuxCNC controller is designed.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH112;TP273

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