Anti-windup FOPI Controller for Step Motor

The performance of anti-wind up fractional order proportional integral (FOPI) controller is tested on step motor. Generally, stepper motor can convert digital signal to angular position. Therefore, controlling of stepper motor is required for precise position with its quicker zero speed tracking performance. By considering practical control limits due to presence of saturation type nonlinearity in the design of step motor control, anti-wind up technique with the conventional controller can be taken to avoid the integrator wind up phenomenon. Here, a modification is done by replacing integer order integrator by using fractional one. PID controller has three fixed parameters. By controlling additional fractional parameters, performance can be improved. Here, by taking this advantageous characteristic of fractional parameters, anti-wind up FOPI controller is developed to achieve faster zero speed response with better tracking reference position.