Logan Ranger Energy Management System for a Prosthetic Limb: Work Night 12.13.18

Date: 12.13.18
Location: Logan HS
Time: 4:30-7:00
Students: Paige, Alex, Avery, Seth and Thomas
Goal: Solder connections on tester and put it under load to see how it performs deflecting the heel 0-1/2". We also want to see how our software program reacts to higher voltages.

We spent the majority of the time trying to get the tester ready to go when put under load. Paige worked on a footpad to create a heel deflection. Thomas and Alex worked on soldering and connecting the electrical. After a broken drill bit, we mounted the foot pad and were ready to test the "limb tester". Everyone got safety glasses on, Thomas energized the system and gradually brought the torque control to full power. Nothing happened! The motor stalled and would not cycle. We were disappointed. We tried starting the limb at different angles but the motor would not cycle the way we anticipated. Later we got it working better and found we cannot start the motor under any load. If we let it build momentum, it will cycle normally and deflect the heel 1/8"-1/4". Now we have to see if we can increase the load to get the 1/2" deflection we need or we have to get a bigger motor.

Seth worked on Inventor to begin designing a mount for the motors and gears. He made good progress considering he had to re-learn Inventor as it has been a while since he used it.

Software Report:

Before we commit to using an Arduino Uno, we want to make sure it will support our input voltages. This is speculation right now, but we may have input voltages ranging from 10 V to 30 V. The I/O pins on an Arduino only support 5 V so a voltage divider has to be created.

Avery worked on some of the background for creating that circuit.

Austin has tested some lower voltages with success, but we want to make sure we can go above 20 V if needed by creating the program and circuit to prove it will work.