Vicon Practice-February 23rd, 2017

This week I had the opportunity to run the Vicon system again. Being familiar with the system definitely helps a ton. During this practice, we did not encounter any new problems! After I controlled the system, I became the subject. I wore shorts so that the knee marker would not be interfered with, like the the first time we captured data, so we were able to capture more accurate data. Just like the first time we captured data, there was an issue with the system where it would switch the identification of the markers midway through the lift. This time we were actually able to correct the system without having to take another capture. This requires identifying the markers in the system multiple times, and it might have just been easier to take another capture, but nevertheless it worked. What we did differently this time was go through the recording frame by frame to see exactly where the markers switched identifications. When that happened, we would pause and rename the markers. Unfortunately this would usually result in the markers being misidentified later in the capture, so we would have to continue going through the capture frame by frame to cut out mistakes. This week was mostly about practicing what I had learned, so I don't have a ton of new information to share today, but I'm looking forward to next week!

Running the System-February 16th, 2017

This week I transitioned from being in front of the cameras, to working the Vicon system behind the scenes. I found this to be stressful because there are a lot of small, easily-forgotten steps that have to be taken or else the system won't function. Everything went smoothly, and we were able to record two good captures. One problem that we encountered this week and last week is that the shoulder marker would disappear at the beginning of a capture. This was easily remedied by moving the marker toward the back of the shoulder. This meant the marker could still be seen when the subject extended their arms forward to grab whatever they were lifting. The problem I see with this solution is that now the marker is no longer recording the position of the shoulder joint, just somewhere around the shoulder. When I originally had the system described to me, I thought that it simply created a field where the markers would be tracked no matter what. But because the system relies on seeing the markers to track them, trackers often don't show up. This has led me to think about a different type of motion capture system that has markers similar to this system but doesn't actually rely on cameras to record the markers. This system would be especially useful for more complex actions and actions where machinery blocks the view of the subject. I'm not sure if this type of system is possible, but it is interesting to ponder. The video I have attached this week shows what the Vicon system shows. Those two lines show the motion of a squat lift!

Starting Motion Capture-February 9th, 2017

On Tuesday of this week, I travelled to Embry Riddle to get my first in depth introduction to the Vicon motion capture software. After that, we were able to capture two lifts, one stoop and one squat lift. Setting up the software is not as simple as just turning on the cameras. All six cameras must be checked to ensure that they are directed at the right spot, and are focused. After this, the field must be masked so that the cameras do not pick up on anything else in the room. The area where motion capture can occur must be declared. This is done by walking in circles waving a T-shaped wand where the subject will stand while they perform the lift. This wand is also used in the next step to declare the X, Y, and Z axes. This is done by placing the wand on the ground. After this, the subject can enter the field. Once the subject enters the field, the markers can be named on the system. For this motion capture, the markers for wrist, elbow, shoulder, hip, knee, and ankle had to be declared. This allows the system to connect the lines to better represent the lift. One problem we encountered this week was that the system was switching the description of the markers during the middle of the lift. This happened when I brought my elbow in close to my body. The marker on my elbow would overlap with the marker on my hip and the system would confuse the two markers. We had to repeat the motion capture for the stoop lift three times because of this but we eventually got good data. Another issue that we encountered this week was that I was too tall to wear the skin tight suit that is usually worn for motion capture(a blessing and a curse). This is an issue because this meant we had to attach the markers to the outside of my jeans. This meant that the markers could move without matching my movement precisely. One solution to this was rolling up my sleeves and pants. The markers were then placed directly on my skin. In the future, I plan on wearing the shorts so that we can capture more accurate data. The videos I have attached are from the lifts. This is not from the vicon software because the vicon software only displays two lines which makes it very difficult to understand what is going on. These videos are recorded on a normal video cameras so that what the software is displaying can be understood. The first video is the stoop lift, the second is the squat lift. In the next couple weeks, I will continue working with the motion capture system, collecting more data. After that, I will begin analyzing my data and movements. 

Introduction-February 2nd, 2017

Hello! My name is Ben Kelty. I am a senior in high school from Flagstaff, Az where I attend BASIS Flagstaff. For the next twelve weeks I will be working on my Senior Research Project at Embry Riddle Aeronautical University in the ergonomics laboratory. For more information on this lab please look here: https://prescott.erau.edu/about/labs/ergonomics/index.html. I will be working with Dr. Maxwell Fogleman for this project. He is the professor of ergonomics at ERAU.  I will also be working with Ms. Katelyn Wyatt, who will be my in school advisor.
The goal of my project is to look at the differences between lifting with your back(the stoop lift) versus with your knees(the squat lift). The old saying says to always lift with your knees, but how accurate is this actually? I will be studying the biomechanics of each lift, and the physiological aspect of each lift. I'm really excited to start learning about the Vicon Motion Capture and Measurement System. This system was used in animating the Hulk's movement in The Avengers and systems like it are used in video game and animated movie development. I will use this system to track the movement of each lift, and then use the data it provides to analyze the lifts. The plan for now is to start learning the software next week, and begin capturing the lifts soon after. Thanks for reading!