Load based Fuzzy Controller for Bipolar Stepper Motor

Abstract

This Stepper motor finds its application widely in the field of robotics and industrial automation. Stepper motors are majorly used in pick and place robots used in warehouse automation. These robots aid productivity by reducing cycle time and increasing production flexibility. In general, irrespective of the weight of the object, power consumption of the stepper motor used in these robots is constant. This results in the wastage of energy and increases production cost. This paper has proposed a closed loop and load based fuzzy logic controller for the stepper motor, which is used in the pick and place robots. The closed loop fuzzy logic controller is implemented using a PIC microcontroller and load cell. **U sing PI controller, it is difficult to control the dynamic motions of a robotic arm. The fuzzy logic approach is used to regulate the torque of the stepper motor for the given load value measured from the load cell. To verify the design performance, simulation model is constructed using MATLAB/Simulink for light, medium and heavy load conditions. The prototype model is developed with 48V Nema 23 stepper motor to verify the simulation results. When compared the results with open loop system, the output obtained in closed loop fuzzy approach is more precise for all load conditions and desirable power saving is achieved.