FLOW RATE CONTROL METHOD IN INFUSION PUMP USING ADAPTIVE FUZZY PROPORTIONAL INTEGRAL CONTROL BASED ON MOTOR SPEED READING

Abstract

This invention relates to a method of controlling the flow rate of an infusion pump using adaptive Fuzzy-PI control based on real-time stepper motor speed readings. The method begins with setting the target flow rate and target volume, then reading the motor speed using a magnetic sensor that detects the rotation angle. The speed data is processed using a moving average method to improve the stability of the reading, then converted into an actual flow rate based on the system calibration function. The actual flow rate value is compared with the target value to obtain the error and delta error which are used as input to Sugeno fuzzy logic. The fuzzy output is in the form of adaptive Kp and Ki parameters which are used by the proportional-integral (PI) controller to regulate the stepper motor speed in a closed control system.This method is able to maintain a stable flow rate, increase the accuracy of fluid administration, and stop the infusion process automatically when the target volume is reached.