两自由度并联机器人控制系统设计

Design of Control System for Parallel Robot with Two Degree of Freedom 

摘要:

针对机电装配、医药包装等行业自动化抓取和放置实际应用的需求,设计了一种采用直线伺服驱动技术的两自由度高速并联机器人；首先进行了机器人的机械结构设计,并且通过运动学分析,结合运用蒙特卡洛法与几何法求解出并联机器人的工作空间；其次采用MCU+CPLD(STM32F103+MaxⅡ)的双控制架构,根据工作空间结构在MCU中设计出高效的运动轨迹生成算法,并在CPLD中运用DDS技术将伺服运动参数转换成脉冲经一级差分后输出到伺服驱动器;在双控制器的通信方面合理利用CPLD中的状态机提出了双级数据缓冲方式,使得MCU写与CPLD读交错进行,可以实现数据的无缝刷新；最后进行了并联机器人系统样机的制作与调试,分析结果表明所研制的机器人控制系统能够使机器人快速抓放金属小球,实现稳定可靠运行。

Abstract:

To fit the demand of automatic pick and place in the manufacture process of medicine packaging and electromechanical assembling,a high-speed 2-DOF parallel robot using linear servo technology is designed in this thesis. Firstly, the mechanical structure design of the robot is introduced, according to the results of kinematics analysis, the workspace of the 2-DOF parallel robot is obtained via Monte-Carlo method and geometrical method. Secondly, a control system consist of MCU and CPLD(STM32F103+MaxII)is adopted, an efficient approach to generating motion curve programs in MCU is proposed based on workspace. And we use DDS(Direct Digital Frequency Synthesizer) to generate square wave in accordance with motion parameters, then we transform square wave to differential signals which will be sent to servo driver. In the design of communication between the two controllers, a two stage data buffer is presented by rational use of state machine in CPLD, which can realize the interleave of MCU read and CPLD write to achieve seamless refresh of data. Finally we complete the manufacture and adjustment of the robot demo, the results shows that the performance of the 2-DOF parallel robot system is stable and reliable, at the same time the robot can pick and place the prill quickly.