一种欠驱动双板分离式采摘器的研制

Research on an under actuated dual separation plate harvestor

【目的】采摘是林果种植中的劳动密集型作业,果园中的果实采收环境较为复杂,我国采摘机具的行业研究相对薄弱,采摘机器人等高科技装备在当前果园采摘中的实际应用还具有一定的局限性,因此发展辅助人工摘果装备具有切实的社会和经济意义。【方法】针对球形带梗果实,以苹果为例提出了果梗锁定—枝果分离的采摘方法,并设计完成了相应采摘器。采摘器整体结构为欠驱动布局,以曲柄摇杆机构为原型设计了果梗锁定机构,构造了固定板、浮动板结构的双板枝果分离机构,利用摇杆滑块机构作为手持驱动单元,利用钢丝和绕线丝轮的传动方法将滑块的输出运动首先传递到曲柄摇杆机构,驱动结构和尺寸对称的两套果梗锁定机构对果梗进行锁定,果梗锁定后继续驱动浮动板向下移动与固定板分离完成摘果。【结果】分析了驱动单元和果梗锁定机构的几何参数,驱动单元的手柄转动5. 5°即可使摘果器完成87°的果梗锁定和50 mm的双板分离动作,果梗锁定机构在锁定果梗时处于反向死点位置,保证了锁定的可靠性。应用Adams软件仿真了采摘器的果梗锁定和双板分离动作,验证了采摘器欠驱动结构的设计可行性,并对输出曲线在锁定果梗过程中的振动情况进行了解释;对采摘过程中的驱动力进行了仿真。采摘器样机实验顺利完成了锁定果梗—枝果分离的顺序采摘动作。【结论】枝果分离的采摘方法和欠驱动双板分离式采摘器在实际应用中具有可操作性,可用于发展人工辅助采摘机具。

[Objective] Harvesting is labor intensive work in planting, orchard harvest environment is relatively complex, harvest machine industry research is relatively weak in our country, harvest robot technology in the current garden application still has some limitations, so the development of auxiliary artificial harvest equipment has a real social and economic significance. [Method] For the spherical fruit with stem like the apple, a peduncle locking-two plate separation harvest method was proposed, and the corresponding harvestor was designed. The overall structure for the harvestor was under-actuated, the crank rocker mechanism was designed for the peduncle locking mechanism, the fixed plate and the floating plate were designed as the branch fruit separation mechanism, slider-crank mechanism was used as a handheld drive unit, through the method of steel wire and the wire coiling wheel, the output of the slider movement was firstly transmitted to the crank rocker mechanism, two sets of symmetrical structure and dimension peduncle locking mechanisms were driven to lock the peduncle, and then the floating plate was driven to move down, together with the fixed plate, the branch and apple were separated to finish the harvest. [Result] The geometrical parameters of the driving unit and the peduncle locking mechanism were analyzed. The 5.5° rotation of the handle in the driving unit generated a rotation of 87° for the peduncle locking mechanism, and further the double-plate separation with a distance of 50 mm. The peduncle locking mechanism was in the reverse dead point position when locking the peduncle, which ensured the reliability of the locking. Adams software was used to simulate the process of the peduncle locking and double plate separation, the feasibility of picking the under-actuated structure was approved, and the output curve vibration in the process of peduncle locking was explained, the simulation of the driving force in the process of harvesting was obtained, the prototype experiment was successfully completed with the peduncle locking-branch fruit separation achieved. [Conclusion] The method of peduncle locking-branch fruit separation method and related harvestor are proved to be feasible in the real manipulation, and they can be applied to help the artificial fruit harvest.