Simulation of Sensorless BLDC Motors and a Two-axis Gimbal Using MATLAB/Simulink

Brushless direct current (BLDC) motors are widely used in many industrial applications because they have several advantages compared to conventional DC motors, including high speed, high torque, and low maintenance. General BLDC motors have built-in hall sensors to detect the rotor position. However, because the output signal from the hall sensors is vulnerable to environmental noise, sensorless BLDC motors are adopted in critical environments. To control the sensorless BLDC motor, it is necessary to estimate the rotor position based on back-electro magnetic force (EMF) signal measurements. Sensorless BLDC motors have the benefits of low cost and compact size and are often used in gimbal systems, which is a type of motion stabilizer that has two or more axes of rotation and requires nonlinear dynamic control. In this paper, a nonlinear dynamic control simulation is implemented using MATLAB/Simulink for a two-axis gimbal with a sensorless BLDC motor.