主路式水肥一体机施肥系统的设计与试验

Design and Experiment of Main Road Water and Fertilizer System

针对现阶段水肥一体化设备存在施肥不均、自动化程度不高及滞后性严重的问题,根据现代化农业节水省肥和减少环境污染的灌溉要求,设计了一款可实现自动混肥、施肥、节水灌溉的主路式水肥一体化施肥机。根据液肥的EC和pH值调节过程的特点,开发了以SIEMENS S7-1200为核心的液肥控制系统硬件,并结合MatLab设计了以模糊PID为控制器的液肥EC和pH值控制系统。为验证施肥机在实际应用中的精确性和鲁棒性,设计了施肥系统动态调节性能试验,结果表明:在施肥阶段,模糊PID控制系统具有较短的稳态时间和较小的超调量,相比于PID控制系统,对EC和pH值进行调节的稳态时间分别减少了37.7%和52.1%,稳态超调量分别降低了1.2%和2.2%,可实现对混肥溶液进行迅速有效的调节,满足现代农业实际生产需要。

In view of the phenomenon of uneven fertilization,low degree of automation and serious lag existing in the integrated equipment of water and fertilizer at the present stage,according to the irrigation requirements of saving water and fertilizer in modern agriculture and reducing environmental pollution,a main road integrated water and fertilizer applicator which can realize automatic fertilizer mixing,fertilization and water-saving irrigation is designed.According to the characteristics of EC and pH adjustment process of liquid fertilizer,the hardware of liquid fertilizer control system with SIEMENS S7-1200 as the core was developed,and combined with MATLAB,the control system of liquid fertilizer EC and pH with fuzzy PID controller was designed.Finally,in order to verify the accuracy and robustness of the fertilization machine in practical application,the dynamic adjustment performance test of the fertilization system was designed.The test data showed that in the fertilization stage.The fuzzy PID control system has shorter steady-state time and smaller overshoot.Compared with the PID control system,the steady-state time of EC and pH value adjustment is reduced by 37.7%and 52.1%respectively,and the steady-state overshoot is reduced by 1.2%and 2.2%respectively,which can realize the rapid and effective adjustment of the mixed fertilizer solution.It can meet the actual production needs of modern agriculture.