狭闭空间内苗盘物流化搬运机器人运动规划与试验

Motion Planning and Test of Robot for Seedling Tray Handling in Narrow Space

针对植物工厂狭小密闭工作空间(狭闭空间)内大范围作业需求,提出了一种应用于植物工厂内部的物流化搬运机器人。采用D-H法建立连杆坐标系,通过求解运动学正解对机器人运动空间进行分析,在此基础上,采用边界追踪法规划了一种满足植物工厂立体式培育特点的滑切式搬运最优轨迹,提取轨迹上若干点,求解提取点运动学逆解,采用三次样条插值拟合机械手臂关节变量随时间变化函数,并在实验室中搭建育秧环境可自动调控的立体式育秧平台进行试验,控制机器人按照最优轨迹运动,应用高速摄像技术对实际运动轨迹进行记录,试验结果表明,实际轨迹和最优轨迹最大绝对误差为8 mm,在误差允许范围内,可以完成植物工厂内所需的搬运作业功能。

Due to the high cost of plant factory,we put forward a logistics handling robot,worked in a wide range but took up a narrow space when in non-working state,based on plant factory. First,we introduced its work environment and task characteristics. The space,which the robot takes up,needs to be minimized as far as possible,what ＇s more,the optimal trajectory must ensure that the distance between the robot and the seeding platform reaches the minimum. Then,we adopted D-H method to establish the connecting rod coordinate system,and analyzed the robot movement space through solving the kinematics equation. On this basis,we planned a kind of sliding handling optimal trajectory to meet the vertical cultivation characteristics of plant factory. Then,we extracted some points on the trajectory and solved the kinematics inverse solution of those points. Next,we fitted time-varying function curve of manipulator＇s joint variable by using cubic spline interpolation. Last,we made a test-machine and set up a vertical seedling platform in the lab. We controlled the robot to move along the optimal trajectory with a high-speed camera recording its actual moving tracking. The test showed that the maximum absolute deviation of actual moving tracking was 8 mm which was within the error range and verified the correctness of the inverse solution. So the invention can complete the needed handling work and provide a good platform for the following study of plant factory.