目的 针对水稻株间机械除草自动化程度低、难度大的问题，在机器视觉识别定位技术研究的基础上，研制一种气动式水稻株间机械除草装置。方法 采用机械设计理论、离散元动力学仿真方法结合田间试验，研制出气动式水稻株间机械除草装置。首先对气动式株间除草机构的结构进行设计，运用运动学方程计算并确定机构的几何参数，通过Pro/E运动学仿真验证机构的可行性；然后对除草刀齿与水田土壤的相互作用过程进行仿真，并对仿真结果进行验证试验；最后进行田间试验验证整机工作性能，并利用三因素五水平二次旋转正交试验对影响除草率与伤苗率的工作参数进行分析。结果 气动式水稻株间除草机构连杆长35.00 mm，摆杆长72.24 mm，除草部件到回转中心水平距离为84 mm，垂直距离为191 mm。离散元动力学仿真分析表明，倾角为10°的弯齿刀除草刀齿与土壤的接触阻力较小，阻力平均值为3.12 N，且对土壤的扰动程度较大，受影响的面积达149.69 cm2。田间试验中，在机具前进速度0.25 m/s、气缸伸缩速度0.45 m/s和除草深度2.5 cm的工作参数下，平均除草率为83.91%、伤苗率为3.63%。结论 该机具满足除草率大于80%、伤苗率小于4%的设计要求，能够满足水稻株间避苗除草的作业要求。
Objective In order to solve the problem of low automation and high difficulty of mechanical intra-row weeding in paddy field, a pneumatic paddy intra-row weeding device was developed based on the recognition and positioning technology of machine vision.Method The mechanism of pneumatic intra-row weeding device was designed by applying the principle of mechanical design, discrete element dynamics (DEM) simulation method and field test. Firstly, the structure of pneumatic intra-row weeding device was designed, and the geometric parameters of the mechanism were calculated using the kinematic equations. The feasibility of the mechanism was determined from kinematic simulation by the motion analysis module of Pro/E. Then, the interaction between weeding blade and paddy soil was simulated and the simulation results were confirmed through test. Finally, the field test was carried out to evaluate the working performance of the whole machine, and the working parameters affecting weeding rate and seeding injury rate were analyzed using a three-factor and five-level quadratic rotation orthogonal test.Result The connecting rod length of the pneumatic intra-row weeding device was 35.00 mm and the oscillating rod length was 72.24 mm. The horizontal distance from the weeding part to the rotary center was 84 mm and the vertical distance was 191 mm. The DEM simulation results showed the better structure was the blending blade claw in 10°, which contact resistance was relatively low with an average value of 3.12 N when contacting with soil and the soil was disturbed to a great extent at this angle with affected area of 149.69 cm2. The field test results showed the device achieved the optimum working performance with the average weeding rate of 83.91% and seedling injury rate of 3.63% when the machine forward speed was 0.25 m/s, the cylinder protruding speed was 0.45 m/s and the weeding depth was 2.5 cm.Conclusion The pneumatic paddy intra-row weeding device satisfies the requirements of above 80% weeding rate and below 4% seedling injury rate. It could meet the requirements of intra-row weeding and seedling avoiding in paddy field.