摘要
针对玉米追施肥机械田间作业通过性及施肥量精确控制问题,设计了一种三轮高架作业车变量施肥系统,该系统由机械排肥系统、液压传动系统和电控调速系统3部分组成。电控调速系统采用闭环控制,以STM32F103R8T6微处理器为控制核心,结合设置的施肥参数和检测到的速度信号,采用增量式PID算法控制施压系统中的电液比例流量阀来调节排肥轴的转速,实现对施肥量的控制,并显示施肥参数、作业车前进速度和排肥轴转速。室内试验表明,排肥槽工作长度为30 mm,排肥量平均变异系数最小,确定了该工作长度下排肥量和排肥轴转速的拟合方程;整定PID控制参数,确定了Kp为1.2,Ki为0.02,Kd为0.4。田间试验表明,施肥量平均偏差为0.84%,平均变异系数为1.852%,实现了对玉米机械化精确追肥。
In view of the problems of traffic ability and the precise control of fertilizer application of the additional fertilizer machinery,the variable rate fertilization system of tri-wheel high frame operation vehicle was designed. It was composed of mechanical fertilization system,hydraulic system and electronic speed control system. Its trafficable height was 1. 2 m,and could apply fertilizer to four lines of corn at the same time. During operation,the hydraulic system powered hydraulic motor to drive the outer groove wheel type fertilizers. The control of fertilizer application was realized by electronic speed control system adjusting the rotational speed of fertilizer shaft, using closed-loop control and the microprocessor STM32F103R8T6 core,combining the setting parameters such as dose rate and the speed signals being detected to calculate the advancing velocity of high frame operation vehicle and the theoretical rotational speed rotational and the actual rotational speed of fertilizer shaft and displaying them,adopting the incremental PID algorithm to control electro-hydraulic proportional flow valve. The laboratory test showed that average coefficient of variation of the fertilizer amount was minimum when fertilizer trough work length was 30 mm. The fitting equation of fertilizing amount and rotational speed was determined. PID parameters was set as proportional coefficient of 1. 2,the integral coefficient of 0. 02,and the differential coefficient of 0. 4. The field experiment showed that the average deviation of fertilizer application was0. 84%,the average coefficient of variation was 1. 852%,realizing mechanized and precise additional fertilizer for corn.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2016年第S1期170-175,共6页
Transactions of the Chinese Society for Agricultural Machinery
基金
基金项目:河南省现代农业产业技术体系玉米全程机械化岗位专项(S10-02-G07/2016)
关键词
玉米
高架作业车
变量施肥
电控调速系统
PID控制
corn
high frame operation vehicle
variable rate fertilization
electronic speed control system
PID control
