摘要
为了解决免耕播种机在秸秆覆盖地作业时由于播种深度不够造成的种子裸露现象,以及提高免耕播种机播种深度的控制精度,设计了一套免耕播种机播深自动控制系统,采用Flex传感器作为仿形元件,建立了其在限深轮内的运动数学模型,推导出了Flex传感器的输出电阻变化率与传感器进入印痕区长度的关系。并据此模型采用3个Flex传感器实时检测限深轮与地面接触时的胎面形变,实现播种单体对地压力的监测。系统根据播种单体对地压力的变化,控制电-气比例阀实时调节气压弹簧对播种单体的下压力,从而保证播种深度的一致性。田间对比试验结果表明:Flex传感器和PVDF传感器均具有可靠的仿形性能,在播种作业速度为2.78m/s时,基于PVDF传感器的控制系统和基于Flex传感器的控制系统均能实现播种深度自动调节功能,但后者的控制精度更高,其控制误差在±8mm之间。
In order to solve the problem of seed uncover caused by shallow sowing depth of no-tillage planter working in straw-covered field,and to improve the control accuracy of sowing depth of the notillage planter,an automatic sowing depth control system was designed.Using Flex sensor as a profiling component,its motion mathematical model in the depth wheel was established,and the relationship between output resistance change rate of the sensor and the length of the sensor entering the imprinting area was deduced.According to this model,three Flex sensors were used to detect the tread deformation in real time when the depth-limiting wheel was in contact with the ground,so as to realize the pressure monitoring of the row unit to the ground.Based on the pressure change,the system regulates the down force of the pneumatic spring on the row unit in real time by controlling theelectro-pneumatic proportional valve to ensure the consistency of the sowing depth.Field test results show that both Flex sensors and PVDF sensors can provide reliable profiling performance.When the seeding speed is 2.78 m/s,both the PVDF sensor-based control system and the Flex sensor-based control system can automatically adjust the sowing depth,but the control accuracy of the Flex sensorbased control system is higher that the control error is within±8 mm.
作者
贾洪雷
朱龙图
黄东岩
王奇
李名伟
赵佳乐
JIA Hong-lei;ZHU Long-tu;HUANG Dong-yan;WANG Qi;LI Ming-wei;ZHAO Jia-le(Key Laboratory of Bionics Engineering,Ministry of Education,Jilin University,Changchun 130022,China;College of Bioligical and Agricultural Engineering,Jilin University,Changchun 130022,China;College of Information,Jilin Agricultural University,Changchun 130118,China)
出处
《吉林大学学报（工学版）》
EI
CAS
CSCD
北大核心
2019年第1期166-175,共10页
Journal of Jilin University:Engineering and Technology Edition
基金
国家重点研发计划项目(2016YFD070030201)
吉林省科技发展计划项目(20160309001NY)
