Characterization of DC brushless motor for an efficient multicopter design

Abstract

The Unmanned Aerial Vehicles (UAV) has recently gained popularity in numerous industries due to its unique capabilities. Multicopters are increasingly replacing conventional helicopters and fixed wing planes as the most commonly manufactured Micro Aerial Vehicles, due to their reasonable price. Unlike the long flight operations of fixed wing planes, multicopters can only be operated for short durations. The performance of multicopter depend on the characteristic of the motor that had being used. Adding further payloads to multicopters will deteriorate the performance in terms of stability and flight time. The objective of this paper is to study the characteristics of brushless direct current motor for the purpose of multicopter design. The experiments to determine the characteristics of brushless direct current motor are divided into two parts. The first part of the experiment is the measurement of lift force, power consumption, and current drain under various loads. The next part of the experiment is the measurement of the propeller RPM. All experiments were conducted using the same propeller, motor and Electronic Speed Controller (ESC) setup. The data collected from the experiments is used to generate five characteristics graphs, which consist of propeller rotation versus throttle, power versus propeller rotation, lift versus throttle, current versus throttle and finally power versus throttle. Besides that, the graph of flight time vs throttle input was estimated. All the data was used to build a reference table to estimate the minimum take-off throttle input and flight time for various multicopter configurations. In conclusion, the reference table and the graphs can be useful in aiding multicopter designers in designing an octocopter.