棉花打顶机自动对行装置设计与试验

Design and Experiment of Auto-follow Row Device for Cotton Topping Machine

为了提高棉花打顶机的自动化水平,以高地隙底盘棉花打顶机为载体,利用传感器技术、电机控制技术和PLC控制技术,结合机采棉品种棉花种植模式,设计了棉花打顶机自动对行装置。该装置主要由检测机构、对行机构、电机控制系统、电子控制系统和控制软件组成。采用RecurDyn软件对检测机构进行运动仿真,探究运动规律,为角度传感器选取提供理论依据;利用角度传感器获取棉株偏行量,建立检测杆转动角度与步进电机步进量和转动方向之间的对应关系,通过控制步进电机的步进量和转动方向实现对偏行棉株的精确打顶;通过人机交互界面对控制系统进行实时监测,以提高驾驶直线度。为避免侧枝干扰,对两侧低侧枝情况控制系统采用位置信息对比方法获取主茎秆位置;对单侧低侧枝情况按原程序执行,田间实测表明该误差可忽略。田间试验表明,与人工对行相比,自动对行平均偏行量减小了8.08 cm,同比降低56.62%,无偏行率同比提高275%。

In view of the development of cotton topping mechanization,it was found that in addition to cutting off the top branch,the highest lateral branch should also be cut off.Although the highest lateral branch will also produce cotton boll,the cotton boll bearing capacity is far lower than that of the lower lateral branch.The topping machine which can cut off the top branch and the highest lateral branch at the same time was designed by some scholars,but the auto-follow row problem was involved,which may result in the highest lateral branch being missed or over hit.Machine-harvested cotton planting patterns were combined,a set of auto-follow row device of cotton topping machine was designed by using sensor technology,motor control technology and PLC control technology.The device was mainly composed of testing mechanism,auto-follow row mechanism,motor control system,electronic control system and control software.RecurDyn software was used to simulate the motion of the testing organization,explore the law of motion,and provide a theoretical basis for the selection of angle sensor.The deviation of cotton plant was obtained by angle sensor,and the corresponding relationship between the rotation angle of detection rod and the stepping and rotation direction of stepper motor were established.The accurate topping of deviation cotton plant was realized by controlling the stepping and rotation direction of stepper motor.In order to improve the driver's straightness,the control system was monitored in real time through the human machine interface.In order to avoid the disturbance of lateral branches,the position of the main stem was obtained by comparing the position information of the low lateral branches on both sides;for the case of single low side branch,the error can be ignored by field measurement.It was showed that the average deviation of the auto-follow row was reduced by 8.08 cm,56.62%and the rate of not auto-follow row was increased by 275%by field experiments.In the past,most of the topping machines only used the way of flat cutting to remove the top of the cotton plant,and the inhibition of the highest lateral branch was still controlled by chemical control.Therefore,only the topping machine was highly modeled.A device was designed to cut the top branch and the highest side branch at the same time.The intelligent control technology was integrated into the machine,and the auto-follow row device was designed,so the topping quality of the cotton topping machine was raised.The design had great innovation.