为解决稻田机械除草作业中除草率低、伤苗率较高等问题,提出一种光学-机械复合除草方法,该方法通过提高水层浑浊度来抑制杂草光合作用,从而达到除草的目的.通过改进传统的螺旋推进装置,设计一种可适用于稻田土壤环境的微型螺旋推进抑草机.建立滚筒转速对螺旋滚筒工作阻力、运行转速的关系曲线;采用显式动力分析模块LS-DYNA对抑草机在稻田有水环境下的工作过程进行仿真分析,建立螺旋滚筒-土壤-水的耦合模型,进行流固耦合的仿真求解,取得抑草机在作业过程中的切削阻力及功率等参数;通过试验槽样机试验,探究水层深度对水层浑浊度影响的变化规律.结果 表明:设计的微型螺旋推进抑草机最优转速为400 r/min;仿真阻力平均值较试验值大5.47%,仿真功率平均值较试验值大6.06%,仿真数据与试验数据的吻合度高,验证了仿真模型的可靠性;当试验槽中水层深度为20、40、60 mm时,浑浊度大于120 NTU的持续时间分别为5、8、8 h.
Design and experiment of a microspiral propulsion weed control machine for paddy field
In order to solve the problems of low weeding rate and high seedling injury rate in the mechanical weeding operation of rice fields,an opticalmechanical composite weed control method was proposed to suppress weed photosynthesis by changing the turbidity of the water layer with the aim to control weed.By improving the traditional spiral propulsion device,a microspiral propulsion weed control machine suitable for paddy field soil environment was developed.The relationship curves between the drum speed and the working resistance and running speed of the spiral drum were established.The explicit dynamic analysis module LS-DYNA was used to simulate and analyze the working process of the weed control machine in the paddy field water environment to establish the spiral drum-soil-water coupling model.The fluid-solid coupling simulation was performed to solve,and the cutting resistance and power parameters of the weed control machine were collected in the operation condition.Through the test tank prototype test,the changing law of the influence of water layer thickness on water layer turbidity was explored.The results showed that the optimal speed of the designed microspiral propulsion weed suppressor machine was 400 r/min;the simulated resistance was 5.47%higher than the test value on average,and the simulated power was 6.06%larger than the test value on average.The simulation data was highly consistent with the performance test data,which verified the reliability of the simulation model.When the water layer depths in the test tank were 20,40,and 60 mm,the duration of turbidity greater than 120 NTU were 5,8,and 8 h,respectively.
paddy fieldweed control machinespiral propulsionoptical-mechanical composite weedingturbiditySPH algorithm
万方数据
维普
