Design of variable rate fertilization control system based on improved PID

To enhance the control accuracy of the variable rate fertilization control system and to solve the problems of long delay time and high overshoot of the variable rate fertilization general PID controller, a variable rate fertilization control system was designed based on improved PID. The structure of a designed variable rate fertilizer applicator was introduced. The fertilizer apparatus and the stepping motor mathematical model were built. An anti integration saturation method was adopted to improve the integral of the general PID controller. An incomplete derivation method was adopted to improve the differential of the general PID controller. The improved PID controller mathematical model and its control block map were built. Finally, the simulation experiment of the step motor rev control were made, which included 80r/min and 120r/min speed tracking contrast experiments. From the simulation experiment result it could be seen that the improved PID controller was better than the general PID controller in terms of decreasing overshoot and shorten delay time.