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.

Week 7

Hi everyone,

This week we decided to create more reference samples containing carbonyl iron and run them through the Q230. The previous carbonyl iron reference sample is known as S-1000 test dust and it contains iron particles with a max diameter of 25 microns. The other two carbonyl iron test dusts are S-3700 which contains iron particles with a max diameter of 6 microns and S-1641 which contains iron particles with a max diameter of 12 microns.  This week I was able to prepare and test reference samples containing S-3700 iron test dust. I was also able to conduct my first ferrograms. To prepare a ferrogram, a sample is mixed with 4ml of hydraulic oil and 1ml of heptane and transferred to a thistle tube. The sample is then metered onto ferrogram slide which is at a decline. Magnets are placed around ferrogram slide creating a magnetic flux which aligns ferrous particles in the direction of the magnetic flux while nonferrous particles are randomly oriented on ferrogram slide. Once the sample fluid has passed across the ferrogram slide it is deposited into a drain, then it is flushed with heptane to dry the slide. Once the ferrogram slide was completely dried, I removed it and looked at the ferrogram slide under a light microscope and took pictures of it. The largest ferrous particles are located closer to ferrogram slide that is closest to thistle tube because the magnetic force acting on a particle is proportional to its volume. I was able to create a ferrogram of reference 18 which contains S-3700 carbonyl iron test dust and is shown to the right at magnification of 40x. 

Final Post

Hey everyone!

Just wanted to wrap up my summer with an overview of what I did. I spent the last ten weeks working on a test platform for a partial stroke piston pressurization pump motor. To do this, I had to design a suitable hydraulic circuit and then implement the details of it ranging from machining mounting plates and selecting hosing to building and calibrating electronic measurement systems. Ultimately, we ran out of time before testing the pump. We did manage to get as far as starting up the supply pump motor and testing all the sensors but the speed encoder. I believe other undergraduates from UMN should be able to finish the project throughout the school year. and then use the test stand to determine the efficiency of the PSPP pump/motor.

Throughout my REU experience, I had the opportunity to pick up several new skills. I learned hands on engineering skills such as how to machine metal and how to build and troubleshoot electronics. I also developed problem solving skills as the challenges I faced in this project were relatively open ended.

To an incoming REU student, I would emphasize the need to develop persistence. Being a good researcher requires intelligence, problem solving, and communication skills, but more than anything successful research requires a willingness to keep going in the face of adversity.

I wish everyone the best of luck in the coming years and I hope we all get to keep accomplishing cool things.

Best regards, 

Mike

Final Post

This summer has been filled with fluid power.

My research consisted of designing an external gear pump and modeling the leakage flow in MATLAB and other software platforms. The goal of the research was to be able to model the leakage flow from a pump based off of the operating conditions and the tolerances of the pump. Our first step in the research was designing the pump in Solidworks so that we could use the specifications in our MATLAB model. Then we modeled the leakage flow in MATLAB and from that, we were able to find the equivalent gap height of the pump.

The next step in the research would be to run experiments on different pumps to see if our simulation data agrees with the data obtained from the experiment. What I learned most from this research experience is that research can be a very long and arduous task, but once one of the goals of the research is accomplished it is a very rewarding feeling and definitely worth all the hard work. Advice that would I offer to future REU students is that you can never ask too many questions and to ask other people in your lab about their research because it may give you ideas for your own research and is not, at least you learned something new.

Unfortunately, I don't think I can attach my PowerPoint presentation anywhere. This has been a great summer, good luck to all of the other REU's.

-Andrew 

Final Post

Its been real and its been fun!

My summer consisted of designing and building a small hydraulic arm that will be used for student outreach in high, middle, and elementary school. The goal was to build off of a previous arm that wasn't reliable. The arm needed to fit a 14inch x 18inch case, plug into the wall, and then be powered by my electrical motors. These motors would then push a syringes filled with water connected to another syringe on the arm, making the arm actuated. My work was not very experimental, but I had the chance to learn very precise 3-D printers such as the Autodesk Ember and the Formlab Form 2,  learned how to run a boss laser engraver, and how to program an Arduino to control electronics. Most of my summer was spent creating my machine in Inventor, fabricating it, and testing out my Arduino programming.

The project wasn't completely finished and will need be to be manufactured and assembled once I leave. Once everything is assembled, testing of the system will need to carried out to work out to find any bugs or design flaws.

My biggest takeaways from my experience were the manufacturing techniques I was able to learn, my new experience with electronics, and the friends I was able to make (you guys :)).

Below is a picture of it in Inventor and
of a prototype I built that wasn't electrically powered:

Final Post

Hi everyone,

I hope you've all been having wonderful summer experiences! I can't believe how quickly the summer flew by.

I've been doing experimental research with an inverted liquid piston air compressor. It involved fabricating different porous media (which are sort of like coarse sponges) and taking high speed videos of the interface between the air and water while running the compressor. I ran tests without porous media, with interrupted stacked plate porous media, and with vertical rod porous media. I also tested the effects of hydrophobic coating for the interrupted stacked plates. I found that longer length plates, wider spacing, and smaller diameters result in greater stability, that compression ratio has little effect, and that the hydrophobic coating results in less air bubbles being entrained in the water but more splashing. My experiments helped characterize interface behavior at different operating frequencies and stroke lengths. This knowledge is important to determine sizing and applications for this technology.

The next steps involve testing different spacing of the vertical rods, testing the vertical rods with hydrophobic coating, designing and testing vertical rods with the same porosity as the interrupted stacked plates, and trying a stepped cylinder that keeps the water height constant when the porous media is plunging into it.

The biggest takeaway for me is the experience of doing research. It's very different from my experiences in internships. The work is much less defined, which can be challenging - with a new technology, there are so many facets to explore, so it's challenging to decide which are most important. I also felt more ownership with my work, as the only person working on the project. I was in charge of every part in my setup and making sure things were running and being analyzed properly.

New REU's should expect to learn a lot about the research experience and fluid power. You'll become an expert in some aspect of fluid power! Research can be frustrating and overwhelming at times - there are so many related papers and textbooks, and it's tricky to balance background reading to better understand what's happening in your project and doing hands-on work for your project. Things also tend to break or behave strangely in research; know that it's okay to be frustrated and to ask for help.

My poster is below. Thanks for a great summer, and best wishes to all of the other REU's!
Rochelle

Final Blog: Summary of My REU Experience

Hello everyone!

We are finally approaching the end of our REU program. Iowa State University was great and Dr. Brian Steward was even better - very open and understanding to my questions (which I had a ton of).

My project was interesting. I was building a test stand that would be used in Iowa State fluid power courses to teach students about cylinder cushions. It was a lot of designing and brainstorming for the best ideas. The overall objective for this project was to have everything running, and we met this goal! The test stand was finalized with sensors and electric circuits, we are able to collect data, and the hydraulic circuit was completed. The next steps would be to have everything more permanent. For now, the test stand was built in a way to have everything work for the time being. We have to clean up the electric circuit box, secure the senors in a more permanent setting, and more.

The ultimate goal of this test stand is to better the computer simulation that we have here. The simulation runs but we are trying to validate this model with physical testing. With more data and maybe better equipment to gather more accurate and precise data, the model will keep improving. An improved computer simulation will allow for a new design process, rather than having to test cylinders through trial and error which costs valuable time and money.

All new REUs should expect the best out of their experiences. While it may be intimidating at first, the experience is well worth it. I have yet to take a Fluid Mechanics course at my home university so I was very scared that I would not know enough of... well, anything! But I have learnt so much during this REU, and I am going back to school with a confidence that I did not expect to leave with.

I hope everyone enjoyed their time as much as I did, but I am very ready to go home.

- Seong


Here is my poster that I will be presenting to faculty and other REU students at Iowa State University!