Final Post

Hey everyone,

My project wasn't directly fluid power related, but revolved around one big fluid power project. My lab this summer was working on a hydrostatic transmission for a 100 kW wind turbine. Since the overall arching project is quite a big one; the assigned project I had was to design and integrate the sensors on the power regenerative wind turbine test platform to a data acquisition system. The process was fun since I got to learn how to create a PCB by myself which allowed for a lot of creativity on the design of the circuit. It definitely was harder than it seemed because I didn't end up finishing implementing the complete circuit. There was a lot of unseen obstacles that popped up as I was going on with my project. While I was able to put in my PCBs, it was hard to find a neat, clean set-up for all the wires coming from the sensors.

This REU taught me so much about fluid power and the industry related to the field. The two graduate students I worked with also gave me some insightful advice about the engineering field. My advice for the future REU students would be don't be afraid to speak up. Ask a lot of questions because people are willing to answer them for you. Also to come in with an open mind and willing to try new things because that's how you'll end up making the most of your summer experience.

Final Post

Hello all,

This summer has been quite the experience. Overall the goal was to develop the foundation for an exosuit that is composed entirely of in-house fabricated soft pneumatic actuators that also provides oxygen to the wearer through a face mask. The challenge was to test the behavior of these actuators in an open system (considered open since the breathing process occurs near atmospheric pressure). More specifically we wanted to collect data on these FREE's (fiber reinforced elastomeric enclosures) and see whether or not it deviated significantly from that of industrial McKibbin actuators and FREE's enacted upon within a closed system. The idea was to see whether we could control actuation with enough specificity in an open system in order to bear a load.
The beginning of the summer consisted of learning about the fabrication process behind the FREE's, although as the summer went on my I was primarily tasked with developing and running setups that would appropriately capture the nature of the actuation process of the FREE's and McKibbin actuators in closed and open system by targeting various points of interest while actuation occurred (i.e. pressure differentials before and after the actuator, flow rate, static change in length after actuation, actuator thickness, and terminal pressure differentials). There was certainly a creative process behind what variables to target as well as uncovering the physics behind the contrast and similarities behind actuation in open and closed systems. The consensus was that the pressure reading after actuator was the variable that was most associated with contraction ratio (this was in an open system, considering in a closed system pressure differentials right before and right after the actuator were generally the same). In order to solidify the idea that pressure differentials right after the actuator was the controlling factor behind contraction ratio, we varied the length of the FREE's and re-ran the data. Similar behavior despite the change in length showed actuation was still associated with pressure differentials after the actuator as opposed to penultimate pressure differentials.
Lastly, we wanted to test force output of the FREE's and McKibbin actuators in open and closed systems. We did this by developing a setup that would accommodate block force testing of the actuators in the systems of interest. Again, we also varied length of the FREE's to see if length affected what we theorized to be the main factor behind contraction ratio. The data was still being analyzed when I finished, so I am not sure if flow rate significantly affected force output of the actuators. Based off of observation of the raw data, it did not appear to significantly affect force output despite there being a drop with increased flow rate.
Overall, the next steps may be to consider the effective multiplicative nature of including numerous actuators in sequence or in parallel to study the effects of these FREE's in various arrangements to begin to acquire an idea behind the optimal setup in a system closely related to the finished product.
My best advice to incoming REU's is to keep an open but empty mind coming into the program. When I say empty mind, I mean not to fill your head with answers ahead of time. Be open to suggestions and to the fact that everything you think, may be incorrect. I believe overall that is a healthy way to go into any unknown situation.

Thanks for the experience!

Final Post

Hello everyone,

It has been a great summer, but sadly it now has come to an end. Going into my project summary, the purpose was to create a hydraulic powered Ankle-Foot Orthosis (AFO) that would be able to emulate any passive AFO. This would allow the practitioner to prescribe the correct passive AFO to a patient within one clinical visit. At the final stages of the project, my role was to make sure the hydraulic AFO would indeed emulate any passive AFO with a range of [0-4 Nm/degree]. To accomplish this, I used various Data acquisition hardware and software along with a Bi-articular Reciprocating Universal Compliance Estimator (BRUCE) to test the apparatus. BRUCE uses a force sensor located on a metal segment that would represent a leg, an angle sensor is also located within a metal segment that would represent an ankle. The data inputted to the computer is the torque applied on the "foot", and the angle displacement. The data gathered was then analyzed through a Matlab script that outputted an averaged stiffness coefficient for each set of data. The problem encountered was that there was a huge variance between the measured and input stiffness. This was due to the elasticity of the bottom shoe platform used within the hydraulic AFO. To compensate for this a variance equation was acquired by creating a linear relationship between the calculated error and the input stiffness. A linear equation for this relationship was acquired, and was added to the command script in the Arduino software, which was the software used to control the system. From here a 65 trial test was performed on the hydraulic AFO and an average error of 2.84% was calculated. This falls within the [0-5%] range needed to consider the hydraulic AFO successful. The next step in this project would be to test it on human subjects and make any minor adjustments to maximize comfort. Also, the next step would be to modify the system and implement an algorithm that would help come up with the most effective passive AFO design according to its application. Altogether this was a great project, and I will be leaving with increased knowledge on hydrolic systems and their applications on bio-medical devices. My advice to any REU entering the research environment is to have as much communication as they can with their adviser and their grad student. They are the ones whom you will learn the most from, but also try things on your own, don't rely on them to solve most of your problems. 

Have a great day guys! It was awesome getting to know you all this summer!

Final Post

My project this summer was "Investigation of a mass flow rate method to evaluate the filterability of hydraulic fluid". It was truly an amazing learning experience for me. Filterability is an important characteristics of hydraulic fluids. However, the current method ISO 13357 to determine the filterability of hydraulic fluids uses the volume method which is time consuming and subject to human error. I worked towards developing a method for measuring the filterability of hydraulic fluids using mass flow measurements, determining the correlation between the volume and mass flow measurements and drafting an ASTM standard test method using mass flow rate.

The REU program itself gave me an opportunity to learn more about fluid power and its application. It has also motivated me to pursue further studies in fluid power and hydraulics engineering. Also getting the opportunity to work alongside with two graduate students have definitely broadened my outlook. My advice for future REU students would be to learn as much as possible about fluid power and ask questions. It definitely helps improving research experience overall. 

Final Post

Hi everyone,

This summer was an amazing experience and I learned a lot about fluid power. A quick overview of my project is that I am trying to evaluate a new technology that counts ferrous particles >25 microns and its iron concentration in ppm. These results are quantitative while other ferrous analytical techniques are qualitative. To evaluate this new technology, I created sets of reference samples containing carbonyl iron and ISO medium test dust and tested them on Q230. I also tested field samples which are known to contain high concentrations of ferrous particles on Q230 and Ferrocheck 2000. I also created ferrograms to relate the results of the Q230. I also related the results of field samples from Ferrocheck to the field sample results from Q230. I found that the Q230 and Ferrocheck 2000 reported similar values for the mean iron concentration in field samples. The Q230 magnetometer system was able to distinguish large and small ferrous particles. The Q230 magnetometer system yielded a linear response with carbonyl iron reference samples and the results are largely qualitative due to variability in the magnetic susceptibility of ferrous alloys. My research project will be continued throughout the year and I will be collaborating with the graduate students at MSOE to complete it.

I wanted to give a thanks to everyone I have met in this program because everyone was amazing and I enjoyed meeting you all. I also want to thank Alyssa Burger for her help in travel and arrangement of this REU program. I would also like to thank my advisor for all his help and encouragement.

To any new upcoming REU participants, this research experience is great and you will learn a lot of useful skill that will be needed for your career. I learned a lot of technical writing skills that I used when writing my research paper. I also gained hands on experience with industry and what techniques is required for research. When I first came into this research I did not know much about fluid power, but after this summer I have learned to love it and will be continuing research in fluid power at my university. The opportunities provided is great and I recommend it for anyone interested in research.
The poster presentation below is what I presented at MSOE and I will be using it to present to Prof. Martini at University of California Merced.

Week 9

Hello everyone,

The Ferrocheck 2000 came in this week. The Ferrocheck 2000 uses a pair of coils to detect the amount of ferrous particles in an oil sample. These coils create a magnetic field when an electric current is going through them. A sample is created when 2ml oil is inserted into a test tube, which is then put on top of Ferrocheck. The sample will enter one of the coils and if ferrous particles are present in the sample, they will interact with the magnetic field created by the coils. The interaction between the ferrous particles and magnetic field creates a current change going through the coils. The amount of ferrous particles in the oil is proportional to the current changes in the coils. The amount of current change in the coils will give the amount of ferrous particles in the oil which is reported in ppm. Before testing the field samples on Ferrocheck 2000, I had to first calibrate it by using the calibration fluids that came with the machine. After calibration, I tested the field samples on Ferrocheck 2000 and found that the particle Ferrocheck was able to detect the iron concentration in the field samples. I graphed the field sample results of Q230 ferrous particle count >25 microns with the Ferrocheck results of the field samples to get the mean value as shown by the picture to the right. This week I also gave an oral presentation in front of multiple audiences and the other MSOE REU students. The Ferrocheck 2000 is shown below.

Week 8

Hello everyone,

This week I was able to prepare reference samples containing S-1641 iron test dust and run them through the Q230. I also created another set of reference samples containing higher concentrations of S-1000 iron test dust and run them through the Q230. I then had a conference call this week with two of the inventors of the magnetometer system embedded within Q230. They were amazed by the results I had gotten from the Q230 with regard to the field samples. Since the Q230 was not able to detect the iron concentration of the field samples, even though they had high iron concentrations, they wanted to see if the particles within the field samples were mostly nonferrous. To check this, they will send over another machine to us to test the field samples with. The new machine they are sending over known as the Ferrocheck 2000 and it detects iron particle concentration in ppm. The Q230 was able to detect the iron particle concentration in the reference samples and has a great correlation coefficient between all the three different particle sizes of carbonyl iron. The graph shown to the right is the results of all the reference samples containing carbonyl iron in ppm on vertical axis, and the horizontal axis representing the actual amount of carbonyl iron in the reference samples. The magnetometer system was able to detect ferrous particles through a wide range of concentrations. A linear response was observed for all three sizes of carbonyl iron particles with a correlation coefficient 0f 0.9612.