自适应振动式稻田株间柔性机械除草性能试验

Adaptive vibration type flexible mechanical weeding test between rice plants

为解决现有稻田株间机械除草作业性能严重依赖机具对行质量的问题,设计了一种无需避苗作业的株间除草机。该机采用双排柔性刷指作为除草部件,前排除草部件纵向梳刷拉拔杂草,同时对梳刷后稻株倒伏状态进行自动识别。后排除草部件横向振动拨耙杂草,同时根据前排识别结果实时控制振动作业的启停,用以兼顾除草率与伤苗率。基于触觉感知方法建立了稻株倒伏识别系统,通过气压传感器的电位变化获取稻株根系与前排刷指相互作用的力学反馈数据,以电位峰度及均值为辨识特征,基于支持向量机构建稻株倒伏与未倒伏辨识模型,实现稻株倒伏自动识别。应用液压马达构建了后排除草部件的横向振动系统,对前排除草部件作用下已倒伏稻株停止振动作业,实现振动作业的自适应控制。稻株倒伏识别田间试验表明:稻株倒伏识别精度为83.11%。除草模式对比试验结果表明:无感知振动模式的除草率为58.11%,伤苗率为21.39%;无感知无振动模式的除草率为27.89%,伤苗率为4%;有感知振动模式的除草率为56.17%,伤苗率为5.83%。综合试验结果可知,有感知振动除草模式更适宜稻田株间杂草机械防控的生产要求。

In order to solve the problem that mechanical weeding between rice plants depends on the alignment of the machine and the seedling belt,an inter-plant weeding machine without avoiding seedlings was designed.The rear weeding component adopts the rake method to remove weeds.It controls the start and stop of the vibration operation in real time according to the front row recognition result.A tactile perception method was proposed to establish a rice plant posture recognition system.Firstly,the data of the roots of the rice plants on the front row of flexible brushes was obtained through the changes in the voltage data caused by the changes in the air pressure by the air pressure sensor.Then,the kurtosis feature and the mean feature in the data were extracted.Finally,the feature vector was substituted into the support vector machine to construct a rice plant posture recognition model.In this paper,a hydraulic motor and rear weeding components are used to form a vibration system,ensuring weeding components can move laterally.When the sensing system detects that the rice plant is fell down,the vibration system will stop working.The field test shows that the recognition accuracy of rice plant lodging is 83.11%.When the sensing system is not working,the weeding rate of the vibration system is 58.11%,and the seedling damage rate is 21.39%.The weeding rate with neither the sensing system nor the vibration system working is 27.89%,and the seedling damage rate is 4%.The weeding rate of the operation with sensing system and the vibration system at the same time is 56.17%,and the seedling damage rate is 5.83%.Based on the test results,the simultaneous working mode of the sensing system and the vibration system is more suitable for the removal of inter-plant weeds in the paddy field.