Science and Mechatronics Aided Research for Teachers with an Entrepreneurship Experience (SMARTER)
2013: Week IV
Timothy Dennis and Peter Tsun
We are working in Professor Kim’s Applied Dynamics Lab. This week our major task was to measure the current through a servo motor. We interfaced and tested the Adafruit Motor Shield with servo motors and DC motors. We discussed with Professor Kim’s team ways to measure current used to move a robotic limb. After an overview of how the robotic arm is controlled we continued to look for the best way to measure the current. We decided that we need to determine the direction of the electrical current through the DC motor. The first thing we tried was to compare the voltage across the motor by measuring the voltages at each terminal of the 18 VDC motor with the analog input pins of the Arduino microcontroller.
Unfortunately, this experiment burned the microcontroller’s ADC . Very quickly, we realized that a microcomtroller’s analog inputs can only take up to 5 VDC. This experience taught us a lesson to never connect anything with a voltage greater than allowable range to the analog pins of the microcontroller. The work that we did with DC motor will help our students design system that protect the digital microcontroller.
Jason Rann and Charisse Nelson
We are working in Professor Gupta’s Composite Materials lab. After making 6 different composite samples, Charisse started conducting strain sensitivity tests. The test shows the point where the materials go from being in an elastics state to a plastic state to its failure point based on being compressed between two metal plates. Each composite material was tested under 3 different rates of compression to represent how the material would respond under extremely slow, medium, and fast compression.
Once all the tests are completed the data will be analyzed to see the different failure rates. Jason heat treated two samples of a magnesium alloy, AZ91. The first sample used the T4 heating process, which heats the specimen to 410 degrees Celsius for 16 hours. Half of those specimens were heated again using the T6 treatment, which heats the specimens up to 160 degrees Celsius for 16 hours. The specimens were then polished to a smoothness of approximately 6 microns. Optical microscopy was performed as well as a Vickers Hardness Test.
The microscopy and hardness data will be compared to control specimens and other materials in the following weeks.
Channa Comer and Dwight Young
We are continuing our research in Professor Profiri’s Dynamical Systems Lab. We are investigating air quality over the Gowanus Canal. Specifically, we are testing the air for the presence of VOC’s (volatile organic compounds), ozone, and nitrogen dioxide.
The presence of these substances will be detected with air quality sensors. After receiving our newly purchased air quality sensors, we developed an interface circuitry on a breadboard to connect the VOC sensor, nitrogen dioxide sensor, and ozone sensor and to calculate the sensor resistance.
Each of these sensors has four pins. A heating voltage VH was applied across pins 1 and 3. A load resistor RL was connected in series with the sensor resistance RS. The use of RL allows us to relate the voltage VS across pins 2 and 4 to the sensor resistance RS. The given heating voltage values were selected to be 2.35V for the ozone sensor, 1.7V for the nitrogen dioxide sensor, and 2.4V for the VOC sensor.
Using the voltage division formula, we determined the following resistance values for the three sensors 77 Ohms across the ozone sensor, 128 Ohms across the nitrogen dioxide sensor, and 80 Ohms across the VOC sensor.
Kelly Brandon, Alexa Goldstrom, Zulficar Habib, and Jigar Jadav
This week in Professor Kapila’s Mechatronics and Controls lab, we have narrowed the scope of our projects related to CAESAR, the humanoid robot.
Habib is currently working on a connection between the android device (via the app) and an Arduino board hosting a WiFly Shield. The Arduino serves as an embedded controller for the motors of the robotic arm.
Jigar has chosen Raspberry Pi as the embedded processor because it is more applicable and accessible to his computer science and robotics courses. He continues to research and work with the Raspberry Pi as the device that will replace the laptop that currently controls CEASAR.
Kelly has the OpenCV library running and has modified the existing code so that CEASAR can learn new faces in a rudimentary way. She is using face recognition algorithms of OpenCV and is beginning to research the current challenges of the area.
Alexa is researching how the anatomical structure of a neck has been used to design previous robotics necks to improve the design of CAESAR’s neck.
All of us met with AMPS/CBSI GK-12 Fellows on Friday and have started developing lesson plans related to our work in the SMARTER RET project.
Linda Dombi and Jason Econome
We are continuing or research in Prof. Iskander’s Soils Lab. This week we planted several different species in the hydrated aqua beads with varying conditions and control groups. We also are testing whether seeds will germinate in the artificial, transparent soils. For our conditions, we used 10 and 15% sucrose solutions, dH2O with 6mg of aspirin, and solutions with 0.1, 0.25, and 0.35g of fertilizer. The challenge is to add the necessary nutrients for growth while still maintaining soil transparency.
The solutions we make must not only have the proper refractive index for transparency, but they also must have the proper pH, turgor, and available nutrients. Through the use of variable testing, the students can see how the scientific method is applied, and how varying conditions affect the organism’s growth. This type of experimentation would give constructive, empirical experience to students in both the biology and chemistry labs.
