Dr. Carlos L. Castillo



Current Projects

Currently, I am working on the following projects:

System Identification of Electrical Motors

The aim of this project is to obtain linear and nonlinear models of Brushed DC motors, Brushless DC motors(BLDC), Permanent Magnet Synchronous motors (PMSM) and AC Induction motors. Currently, a simple test stand have been implemented to obtain the linear model of DC Brushed motors. This test stand consists of a Pololu MC33926 Motor Driver Carrier, a small protoboard, a quad 2-input NAND gate IC 74LS00, a National Instrument Low-Cost M Series Multifunction Data Acquisition PCI-6229 card. The DC motor shown in the figure has an Optical Quadrature Encoder with 300 PPR (pulses per revolution) and a gear ratio of 30:1., 200RPM, 12 V.

A LabVIEW vi have been developed to record the speed response when the duty cycle of the H-Bridge connected to the motor is varied randomly. The PWM signal has a frequency of 20 KHz. The duty cycle was allowed to vary from about 10% to 100%. Next picture presents the Front Panel of the LabVIEW vi.

The corresponding Block Diagram is presented next

The random duty cycle signal generated and the output response (encoder's frequency) were saved to a file. After this, the data was imported to MATLAB and processed using the free available University of Newcastle Identification Toolbox (UNIT). The discrete-time DC Motor Speed model obtained with the UNIT is an ARX (Autoregressive Exogenous) with the following structure

Model Structure

Next, some of the analysis plots, displayed by UNIT during the identification process, are presented

Output Data vs Model Output


Estimated Frequency Response

The discrete-time model obtained is shown next:

DC Motor Discrete-Time Model

Solar Powered Robot

The ultimate goal of this project is to develop a robot for "surveillance" capable of completely autonomous operation, capable of 24/7 service. GPS capabilities and a videlo link will be included in the robot. The main computer will be running Ubuntu and the guidance, navigation and control system is expected to be implemented using the Robot Operating System (ROS).
Next, we were testing that the robot was capable of manuevering while supporting the weight of the 100w solar panel (15lbs). This solar panel, under full sun linght, is capable of providing all the power needed for operating the computer, camera, video transmitter, microcontroller board, motors, and at the same time recharge the battery.

Autonomous Hexacopter

The goal of this project is to build an hexacopter.  The frame has been built and is presented in the next figure


Now, the APM 2.6 autopilot system has been installed as shown in the next figure
Hexacopter with the APM 2.6
The software configuration is in progress. Some testing have been done but a motor need to be replaced.