Construcción de un Circuito Controlador de Movimiento del Motor de un Transductor Sectorial Mecánico Utilizado en Ecografía, mediante Control PID.

Abstract

The project aims to control the position of the piezo electric crystal of a mechanical sector transducer. A control loop with negative feedback is proposed by means of a PID controller. As a reference signal for the crystal’s position a triangular wave is used indicating the type of movement to be performed. A mathematical model for the transducer‘s motor is developed and the model’s parameters are calculated from its response to a square wave. Then a transfer function for the PID controller that is appropriate for the mathematical model developed is determined using SISOTOOL from MATLAB. By placing zeros in the S-plane the percentage overshoot and settling time of the system’s response to the step signal is minimized. Afterwards the controller circuit is implemented using OPAMPs, calculating the values for resistors and capacitors used in the various blocks of the PID controller with MATLAB.