四自由度关节型采摘机械手轨迹规划与实验研究

摘要

According to the demands of cucumber picking task,an articulated picking manipulator with four rotary joints is designed,and a collision-free trajectory planning algorithm in joint space based on cycloidal motion is proposed by considering the structure characteristics of the picking robot system.The planned curves of displacement、velocity and acceleration based on the proposed method are smooth and continuous,which could ensure stability of the manipulator during moving;moreover,it can reduce the computational complexity and improve the real-time performance of the system by transforming obstacles into the joint space to deal with.The realizing steps of the proposed method are descibed in detail,and it' s applied to the practical work of picking cucumbers in the greenhouse,experimental results show that the manipulator can move stably and reliably during picking operation process,and can also move to the target cucumber successfully without collision with other cucumbers and vision system,which could effectively validate the reasonability of the proposed method.%根据黄瓜采摘作业需求,设计了一套四自由度关节型采摘机械手,并结合采摘机器人系统结构特点,提出了基于摆线运动的关节空间无碰轨迹规划算法.该方法不仅能使规划出的运动轨迹、速度和加速度连续平滑,保证机械手运动过程的平稳性;同时将采摘过程中遇到的障碍转换到关节空间进行处理,降低了规划求解的计算量,提高了系统实时性.详细描述了该算法的实现步骤,并将其应用于温室环境下的黄瓜采摘作业,实验结果表明,四自由度关节型机械手在采摘黄瓜过程中运行稳定可靠,能顺利到达目标点进行采摘,不会碰撞其他果实;也不会出现与视觉系统发生干涉的现象,有效验证了所提出轨迹规划算法的合理性.