Date of Award

Spring 2018

Document Type


Degree Name

Master of Science (MS)


Electrical and Computer Engineering

First Advisor

Ababei, Cristinel

Second Advisor

Schneider, Susan

Third Advisor

Yaz, Edwin


The objective of this thesis is to design a hybrid sensorless closed-loop motor controller using a combination of Field-Oriented Control (FOC) and Direct Torque Control (DTC) for brushless DC motors used in multi-rotor aerial vehicles. The primary challenge is the wide range of desired working speeds, which can quickly vary from low speed to high speed. For this range, the control approach must be efficient, effective, and low-cost in order to provide fast response times during initial startup, steady-state, and transient operation. Additional design challenges include minimal response time to desired speed changes and small steady-state speed errors. Finally, the control approach must be robust to motor parameter uncertainties or variations and the operation of the final design must be robust to measurement noise.