摘要
为了解决秸秆粉碎后抛式免耕播种机田间作业时,碎秸装置入土灭茬造成作业负载大、秸秆输送装置拥堵和卡滞的问题,该文研制了基于双扇形孔金属检测圆盘和接近开关的扭转变形采集装置,以有效监测驱动轴的转速和因扭矩负载变化引起的驱动轴错位角。设计了基于32位ARM CortexTM-M3核微处理器的碎秸装置离地高度自动控制系统,实时采集驱动轴转速和错位角,分析其变化趋势,辨别作业工况,输出相应电磁阀控制信号,驱动液压缸适时调整碎秸装置的离地高度,稳定作业负载。试验结果表明,在2 500 r/min的驱动轴额定转速下,碎秸装置离地高度的改变使作业负载变化时,自动控制系统使驱动轴的转速控制在2 448~2 632 r/min之间,驱动轴错位角的变化量为±0.002 4 rad,控制信号对错位角变化的响应延时为0.24 s。田间试验结果表明,利用碎秸装置离地高度自动控制系统后机具的通过性极大改善,堵塞现象消失,作业效率提高52.9%,碎秸作业后地表残茬高度降低43.4%。该设计利用驱动轴转速和错位角的变化趋势辨别作业工况,消除了机械结构参数和材质差异等因素对驱动轴错位角的影响,可为相关农机具扭矩负载定性监测提供借鉴。
As the core technology of mechanized conservation tillage, no-tillage sowing is a new type of agricultural cultivation method popularized in recent years, it directly sows in the field where the straw and roots of the former crops are left, which not only reduces water evaporation and soil erosion, but also can ensure the germination and growth of seeds, which is conducive to water storage and conservation, increasing production and income, and at the same time improving soil fertility to some extent. However, after the harvest of the former crops without any collection and removal treatment, the "full amount of straw field" has become the new normal state of China’s cultivation. The traditional no-tillage seeding equipments are prone to easily increase the workload of straw crushing device when it entering the soil and extinguishing stubble, which causes the blockage and jamming of straw conveying device. In order to solve this problem, the back-throwing type no-tillage straw smashing planter was taken as the research object in this paper, and an automatic control system based on off-ground height of the straw smashing device was developed. Torsional deformation acquisition device was created based on a double fan-shaped through hole metal detection disc and proximity switch, which was installed at both ends of the driving shaft to effectively monitor the rotation speed of the driving shaft and the stagger angle caused by the change of torque load. The design was based on the 32-bit ARM CortexTM-M3 core microprocessor hardware platform, which constituted the data acquisition and output drive unit of the automatic control system, the driving shaft rotation speed and stagger angle was collected in real time, the change trend was analysed through the system software, and current working conditions was identified. According to the corresponding output control signal, the straw height adjusting mechanism timely corrects the off-ground height of the straw smashing and conveying device to stabilize the working load. The straw height adjustment mechanism was composed of a solenoid valve, a hydraulic cylinder, a fixed bracket and a supporting ground wheel. The hydraulic cylinder’s high pressure driving oil was taken directly from the working tractor to improve the applicability of the device. The performance verification test showed that under the driving shaft’s rated rotation speed of 2 500 r/min, when the height of the straw crusher off the ground changed the working load, the automatic control system controled the rotation speed of the driving shaft between 2448 and 2632 r/min, the change of the stagger angle of the driving shaft was ± 0.002 4 rad, and the response delay time of the control signal to the change of the stagger angle was 0.24 s. The field operation comparison test showed that when the back-throwing type no-tillage straw smashing planter was equipped with automatic control system based on off-ground height of the straw smashing device, the passability of the machine was greatly improved, the occurrence of blockage was eliminated, the operation efficiency was increased by 52.9%, and the height of surface stubble was reduced by 43.4% after straw smashing operation. In conclusion, The design of this paper uses the change trend of the driving shaft rotation speed and stagger angle to identify the working condition, effectively eliminating the influence of mechanical structure parameters and material differences, and the mechanical structure is light and easy to install, which can provide reference for qualitative monitoring of torque load of agricultural machinery.
作者
吴惠昌
胡志超
吴峰
顾峰玮
邱添
张延化
陈有庆
Wu Huichang;Hu Zhichao;Wu Feng;Gu Fengwei;Qiu Tian;Zhang Yanhua;Chen Youqing(Nanjing Institute of Agricultural Mechanization,Ministry of Agriculture and Rural Affairs,Nanjing 210014,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2019年第24期1-9,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
中国农业科学院创新工程(绿色耕作与土下果实收获机械化)
国家绿肥产业技术体系(CARS-22)
关键词
农业机械
秸秆
离地高度
错位角
自动控制
agricultural machinery
straw
off-ground height
stagger angle
automatic control
