株间除草装置的除草和避苗状态切换控制系统设计

Design of Switch Controlling System between the State of Weeding and Avoiding for Intra-row Weed Mechanical Control Device

基于除草爪齿余摆运动的株间除草装置利用除草轨道和避苗轨道实现除草爪齿爪尖的除草和避苗两种运动。为保证除草效果和低伤苗率,要求除草爪齿在除草和避苗两种工作状态之间的切换快速、稳定。利用双向转角电磁铁控制引导式轨道切换机构自动切换,采用两个限位传感器检测引导换轨机构是否切换至目标位置和监测引导换轨机构是否受外力被迫运动离开目标位置,并及时控制纠正。引导式换轨控制系统性能试验结果表明：当引导式切换机构碰撞到沿轨滚动轴承时所需时间明显长于无阻挡时所需时间,当有阻挡时旋转角速度越快所需时间越小;引导换轨机构10ms内可完成切换动作,且从除草轨道转动至避苗轨道所需时间和从避苗轨道转动至除草轨道所需要的时间基本相同;旋转角速度为1.257~10.573rad·s^-1时,除草爪齿的除草状态和避苗状态相互切换稳定可靠,可满足株间除草要求。

In order to ensure the claw tooth tips enter to the intra-row spaces for weeding and avoid crop plant damage, switch controlling was studied for the smooth switch between weeding and crop plant avoiding orbits. A two-way electromagnet controls the automatic switch of the orbit mechanism, with two limit sensors to detect whether the orbit switching mechanism is at the target location and monitor whether the mechanism moves away from the target location due to external force for timely correction. Performance tests on the guide orbit control system showed that when the orbit switching mechanism collided with the roller bearing, the required time was significantly longer than that without any obstruction. When obstruction existed, the faster the angular velocity was, the smaller the time required. The time for switching from weeding orbit to crop plant avoiding orbit and for switching back was no significant difference, less than 10ms. The switch controlling can meet the stable and smooth switch between the working conditions of weeding and crop plant avoiding in the range 1.257-10.573rad·s^-1 of angular velocity.