A hob-type smart weeding machine for use in wheat fields: Towards a low power consumption and high-efficiency design

Smart weeding machine is an important tool for control of farmland weeds. To solve the high power consumption, low weeding rate, and high seedling damage rate of existing smart weeding machine in wheat fields, a power consumption model was established for the weed-soil- machine interactions process and a hob-type smart weeding machine of wheat fields was designed. The cutting-edge angle, roller radius, number of hob blades, and hob blade thickness were separately 20°, 85 mm, 8, and 2 mm. A three-dimensional (3-d) structural model of the hob-type smart weeding machine was established on ProE and the operation process of the smart weeding machine’s actuator was dynamically simulated in the discrete element method environment. On this basis, changes in performance indices including the operating width, operating depth, soil-throwing width, accumulation thickness, and average power consumption during the operation were investigated. Field tests of the hob-type smart weeding machine show that the operation width is 202.8 mm, which covers the inter-row area in wheat fields; the operation depth is 36 mm, at which roots of most weeds in wheat fields can be cut or pulled out; the soil-throwing width is 304.2 mm and the accumulation thickness is not higher than 20  mm, which is much lower than the height of wheat plants in the tillering stage. The average power during operation is 197.70 W, the weeding rate is 98.93 % and the seedling damage rate is 4.35 %. Compared to existing weeding machines reported, when the weed removal rates are similar, the power consumption of the weeding actuator developed in this study for wheat fields is reduced by approximately 54 %. On the premise of a comparable seedling damage rate, the weeding rate is increased by approximately 10 %, demonstrating notable characteristics of low power consumption and high efficiency.