基于模糊控制的水肥一体化pH值控制策略研究

Research on pH control strategy of water and fertilizer integration based on fuzzy control

近年来,各级部门大力推广水肥一体化技术,提高水肥的利用率,节约水肥资源。目前国内的水肥一体化系统还存在智能化水平低、混肥精度不高和pH调控不精准的问题,针对水肥一体机调节水肥pH值过程的大滞后、大惯性、数学模型不确定的特点,本论文将模糊控制应用于水肥一体化设备,设计调节水肥pH值的模糊控制系统。用Matlab软件对此系统和传统的PID控制系统进行对比仿真,试验证明该系统能够满足精准施肥过程中对pH值调节的控制要求,并且该系统具有更小的超调量和稳定时间,超调量减少32%,调节时间减少90 s,以及更强的抗干扰能力的特点,恢复时间减少90 s。仿真效果理想,可以将此控制策略应用于水肥一体化控制设备中。

In recent years,departments at all levels have vigorously promoted water and fertilizer integration technologies,improved the utilization rate of water and fertilizer,and saved water and fertilizer resources.At present,the domestic water and fertilizer integration system still has the problems of low intelligence level,low precision of fertilizer and inaccurate pH regulation.In view of the large hysteresis,large inertia and uncertain mathematical model of the water and fertilizer integrated machine to adjust the pH value of water and fertilizer,this paper applies fuzzy control to water and fertilizer integrated equipment,and designs a fuzzy control system to adjust the pH value of water and fertilizer.This system is compared with the traditional PID control system by Matlab software.The test proves that the system can meet the control requirements of pH adjustment during precise fertilization,and the system has smaller overshoot and stabilization time,32%reduction in overshoot,90 s reduction time,and stronger resistance,90 s reduction of recovery time.The simulation effect is ideal,and this control strategy can be applied to the integrated water and fertilizer control equipment.