Self-adjustable fuzzy PID control for solution pressure of pipeline spray system in orchard

Orchard pipeline spraying system has the characteristics of non-linear, apparent delay and a fluctuating pipeline solution pressure along with the changes of nozzle amount. For solving this problem, a self-adjustable fuzzy PID control strategy with differential preceding and gearshift integral was applied on the pipeline solution pressure control. Based on the difference between current pressure and target value, as well as the difference trend, controlling parameters for pipeline solution pressure control were achieved by adjusting the fuzzy PID parameters online and calculating the control variables with the PID algorithm of gearshift integral and differential preceding. Experimental results indicated that, compared with other strategies without the fuzzy PID algorithm, the responding time for pressure rise and adjustment were shortened by 18.42% and 12.56% respectively. The maximum overshoots and system error were reduced by 4.43% and 50% respectively. This method can meet the requirements of pressure control for orchard pipeline spraying system.