International Journal of Computer Science Issues

More than a traditional journal...

The brushless DC motor (BLDCM) is a multi-variable nonlinear control system with strong coupling, which is designed to overcome limitations of the continuous domain control method. Discrete-time sliding mode observer (DSMO) sensorless control of the BLDCM is proposed based on the exponential approach law. The Sigmoid function is used to weaken the chattering problem, and an electromotive force observer is built to extract the electromotive force signal directly. Lyapunov theory is also used to prove the stability of the algorithm. In order to estimate the position and speed of the rotor accurately, a Coordinate Rotation Digital Computer (CORDIC) algorithm is introduced. Experimental results demonstrate that the control strategy can accurately estimate the position and speed of the rotor weaken the chattering problem of the observer and improve the system precision and reliability.