Embedded measurement of torque and speed of a brushless motor for Quadrotors

• Grant number: 16/21843-4
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): April 01, 2017
• Effective date (End): June 03, 2019
• Field of knowledge: Engineering - Electrical Engineering - Electrical, Magnetic and Electronic Measurements, Instrumentation
• Principal researcher: André Carmona Hernandes
• Grantee: Nathalia Marcatto Scurachio
• Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

In aerial robotics applications, brushless motors are a common choice as actuators. Literature review suggest that dominant equation of this type of motor are like brushed ones. Thus, the output power of this actuation system depends on rotor speed and drained current. Therefore, measuring speed and current in flight allows to estimate power, leading to a rough estimative of overall consumption. Moreover, this additional information can be added in control loop. This work aims to develop an embedded measurement system of mechanical conjugate (which comprises rotor speed and torque). The rotor speed will be measured directly and the torque will be inferred by the drained current. It will be used an optical sensor as a speed sensor, based on an infrared emitter/receiver pair. Tests will have distance from motor and size of reflexive strip to find an optimal operation point. For the amperemeter, a reference resistor and a Hall sensor will be compared. Both developed sensors will be tested with a commercial sensor for calibration. (AU)