基于并联机器人的块状食品包装定位方法

目的为提高包装过程中并联机器人定位精度。方法基于自抗扰控制设计一种机器人末端执行器定位方法。在传统并联机器人结构的基础上配置2台工业相机。根据双目立体视觉检测原理来确定块状食品在生产线上具体位置。为避免干扰因素降低机器人末端执行器抓取精度,设计一种自抗扰控制器,主要包括跟踪微分器、非线性反馈器、扩张状态观测器。最后,搭建实验平台并进行相关验证。结果实验结果表明,实际位置与抓取位置之间偏差距离的最大值为0.3 mm;平均误差只有0.20 mm。所设计自抗扰控制器与PID控制器相比,响应时间仅增加了1%,平均抓取精度却大幅提高。结论所述基于并联机器人的块状食品包装定位方法可使末端执行器在非常短的时间内到达指定位置;运动过程稳定、可靠,不会出现振动现象,可确保抓取精度。

Positioning Method of Block Food Packaging Based on Parallel Robot

The work aims to improve the positioning accuracy of parallel robot in the packaging process. A positioning method of robot end-effector based on ADRC was designed. Two industrial cameras were configured on the basis of the traditional parallel robot structure. According to the binocular stereo vision detection principle, the specific position of block food on the production line was determined. An active disturbance rejection controller (ADRC), including tracking differentiator, nonlinear feedback controller and extended state observer, was designed to avoid interference factors reducing the grasping accuracy of the robot end-effector. Finally, the experimental platform was built and relevant verification was carried out. The experimental results showed that the maximum deviation distance between the actual position and the grasping position was 0.3 mm and the average error is only 0.20 mm. Compared with PID controller, the response time of ADRC only increased by 1%, but the average grasping accuracy was greatly improved. The positioning method of block food packaging based on parallel robot can make the end-effector reach the specified position in a very short time. The motion process is stable and reliable, without vibration, which can ensure the grasping accuracy.