I noticed a self-trend with these posts here that apparently somehow 4-5 people stumble upon without me actually "promoting" this page anywhere. That is the bi-yearly post trend. The last post was live back in June, and since there is a time lag between the photos, the post ended with photos from the Christmas of Lockdown. Guess what this means for this post?
Depending on when it goes live (I'm writing this in the middle of October and I think it's going to be posted by December), you'll find photos from the summer season, and some other updates about things in general. Not that the world needs my opinion on things, because there's already too many of them. (Opinions, not people, although, the second one is debatable)
[Mid-Post-Update]
Looks like this post will be posted pre-posting time of previous posts. I'll post myself off...
[/Mid-Post-Update]
Trying to stick to the patterns again, let's start off with the project I'm involved in.
Starting with the fancy robot, we are still iterating the design for the gripper to get a repeatable and precise handling method for the wire which needs to be manipulated. After some basic testing, we improved the base design to localize the position of the wire better inside the grippers. However, initially, we were using FDM/FFF printing, which is the most common type of 3D printing where a plastic filament is melted and extruded through a nozzle. It's simple, but depending on the nozzle size it is usually a bit "streaky" for the lack of a better term.
Because the tolerance requirements are quite tight, we needed precision parts, and that's when we shifted to SLA or Stereolithography. It uses a resin base that is cured to a solid using a UV laser, in the most common designs. The strength of the parts isn't usually high and it takes a lot more time to print, but the prints are extremely high quality and precise as compared to FDM prints.
Not only do we use SLA for the gripper prototyping now, but also for the "core" of the project, again because of the high finish and precision required in the parts.
But the robot process is maybe only 40% of the process that we need to automate. The bulk of the wire handling system is to be designed to... wait for it... Handle the wire.
The actual hardware design was not done by me, obviously because I am no good in CAD modeling, but the other HiWis did a pretty sweet job of the whole system. Now a system was in existence, we need to make it move, and that was again a job for the Arduino. It's predictable, isn't it?
[Edit:- Sorry, no photos allowed, use your imagination to tell me what the system looks like, and I will give you a cookie if you're correct.]
For the wire handling system, the system ends up having 3 stepper motors that control the "flow" of wire through the process. My initial concept was to use 3 encoders to track their rotation directions, and for each "click" or step of the encoder, the associated stepper motor moves a certain amount of steps. An attached LCD screen keeps the track of the stuff that's happening. Seems simple enough. Too good to be true.
Turns out that encoders require the use of Interrupts, which is a whole block of the topic of microcontrollers and software development that I have sadly actively avoided. And usually, interrupts are hardware-based, which means that the ATMega328p based Arduinos all only have 2 interrupt pins, and thus can only use 1 encoder hardware-wise. If you are interested in interrupts and interrupt handling and encoders please look elsewhere, I do not understand these concepts well enough to explain them to you, dear reader.
Anyhoo, I had a brainwave of using only 1 encoder and using the integrated pushbutton to switch between which stepper motor is being controlled. Since I'm also not a "coder", I had to ask my neighbor CS student for help. And soon enough, I was able to toggle and control the motors I wanted to control.
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| As you can see, I keep my working space extremely clean and tidy [Rant] This is what Engineering is for/to me, building testing and breaking stuff, not pulling my hair over weird looking symbols on a scratchy piece of paper, solving complex equations by hand in a time crunch only to later realize computers can do the same things multiple times a second without making errors, and then totally losing it. [/Rant] |
However, the current situation is still far from ideal. The first point of shame is that I did not take into account the masses of objects that are to be moved by the steppers. This is a real shame because I am technically a Mechanical engineer. The problem occurs for heavy objects or fragile objects being handled by the steppers. In our case, sudden movements of the stepper cause the wires to jump or break or behave unpredictably when the stepper motors are activated. The solution to this problem was to implement AccelStepper library, which basically adds an acceleration profile to the motor, thus starting up and slowing down the motor gently, and giving time to the wire to react. The second problem is the simultaneous movement of stepper motors. Because of the way the storage system is designed, one motor releases the wire and the other has to catch and store it to maintain the tension of the wire in the system. And we still need to do some tests to determine the appropriate motor RPMs in such a case, along with a way to move 2 steppers at the same time using AccelStepper.
The final and perhaps the most challenging issue is the communication of the Robot system with the custom Arduino stepper motor system. Because the whole system is supposed to be automated, we need a way to control the storage system, which means the Arduino controlling the stepper motors, from the ABB robot directly. In our basic research, it seemed to be pretty straightforward because the ABB robot supports multiple standards of communications, and I was certain that someone would already have had tried to do a communication link between the robot controller and the Arduino because people have done almost everything possible with the Arduino. But it is turning out to be not so easy. This is still a developing situation, as they say in the daily news, so I will try to update you when we have a solution.
For now, it's mostly doing trail runs and manual testing with just the storage system to find something that should be close to the optimal automated braiding process. The robot is not being used at the moment because of the grippers and the challenges faced in the programming of the robot with an ever-changing setup of the rest of the system. Also, I am still trying to figure out the dual-arm parallel motion execution of stuff. Shit's hard, to be honest.
For anyone else attempting to control 3 (or more) stepper motors from a single encoder and an Arduino Uno, I hope you find the attached code snip useful. For the drivers of the stepper motors, A4988 satisfies my requirements, but other drivers should also work with minimal modifications. Especially the ones having 2 control pins, namely STEP and DIRECTION.
Pastebin - 3 Steppers controlled by 1 Encoder
PS- This is a hacky code. It's terribly documented and not properly explained. Wiring is kind of explained in the code itself.
The rotary.h used here is from Buxtronics's Github, since this was the only one that worked reliably for me. If you are feeling adventurous, you can try other encoder libraries, like GyverEncoder. This is only to make the encoder work properly. Actual stepper motor control is through AccelStepper 2 wire config only.
Apart from all this, the summers really gave me an opportunity to connect with my student-neighbors, which for whatever reason were not in very active contact. After helping me with the Internet situation, there were quite a few instances of conversations and discussions, and I'm always happy to host people in my little room. From watching the UEFA match to "trying" to study together while playing and discussing nice music and other hobbies and interests, it is almost starting to fill the gap of social interactions and connections left by the pandemic.
Not only that, we managed to go on hikes and travel around together. That was a nice change of pace where I have some company and don't have to tow all the stuff myself.
I always thought and I still believe that the majority of the point of doing a Master's or any other education from another country is just the whole experience gained and connections made during that time. No amount of education will possibly be able to replace experiences. Perhaps that is why after a certain point, job (and in a broader sense) life experience matters more as compared to the grades you got or where you got them from. No hate on people doing online courses, but you are missing almost 90% of the whole experience. I know because I was also doing the same over the past 3 semesters, and the most disturbing thing I've realized is academically, it has not made much of a difference for me. But that's also largely because my course is just terribly structured for what it is supposed to be.
Just the act of going out, trying new things, and interacting with people can be extremely rewarding. While on a cross-state trip to Koblenz, we met a great chap from Manchester trotting along and admiring all the fancy vintage trains at the DB Museum. Credit to him because he opened the conversation as I am still a bit of a sissy in that aspect, but ultimately he tagged along with us as he had not explored Koblenz, which was our plan exactly. And that's how I know David Frankal. It's highly unlikely that I'll meet him in person again, but if and when I do, we'll sure go for coffee. :)
Yes, pictures will be posted here in this post or the next one. Or maybe split evenly across.
Now that the pandemic seemingly is in its last stretch, in-person lectures are slowly being organized again, and this was in fact the first time in 3 semesters when I was back in a lecture hall with other humans in presence. Sadly it only took me 1 lecture to realize that in-person lectures aren't really for me. Even ignoring the time penalty of dressing up and going to the lecture hall, lectures especially feel like a bad version of a live stream, with no option to record it or watch later, and adding the additional background noise of squeaky benches and chatter. Thankfully some subjects are still online only. I really hope I manage to pass them so I don't have to deal with them again.
It's funny how Germany's most renowned technical university has made me hate the very thing I came to learn. Surprisingly and sadly, It is not just me. I have talked to 3-4 more students and the general consensus seems to be "It's not worth the time or the effort". Reasons range from the additional time required to get the same educational qualifications because of the difficulty level, to just poorly designed courses that are not practical/ lab focused. One of the student co-workers simply said to me that the whole process of writing and submitting your thesis is too tiresome. Another one said that for the Master's course he wants to attend, there are actually only 2 subjects that he would like to do and the rest are not what he wants to deal with. And the final kicker being an E-mail we received from the student representative body of RWTH. (July 2020)
Particularly important for us is the advancement of our syllabi, especially in the study course B. Sc. Mechnanical Engineering. Up to now, our students graduate after periods significantly above the designated standard. Also, many students abort their studies as late as their 5th semester or later. There are few elective subjects and Informatics plays a minor role. Those issues are at least known since the RWTH-intern study-course-evaluation in 2016. And yet, they did not lead to a successful analysis with the structure of the study course.
It ends up making me feel better about myself. Whatever floats my metaphorical boat.
[Mid-Post-Update]
We got a mail recently announcing scholarships for students who "finished their studies in the standard study period", which means any student sticking to the schedule is actually extremely talented, which is a weird way of saying our course is going to mess you up. And the reward is 25% off on the last semester's tuition fee, which in my case is able to be compensated by 2 months of HiWi-Job. And yes, I have a tuition fee.
[/Mid-Post-Update]
Also, a quick shout-out to the transport associations of Germany and Aachen for giving the free travel offers over the summers. Thanks to that, me and my sister were able to visit almost all of the key cities in NRW for free. I hope they continue offering similar offers in the future because that made me realize the economic impact such plans almost certainly have. As you will see from the pictures below, it's a lot of big and small places nearby I managed to sneak to on my trustee bike. Obviously, I took a lot of photos, so I'll sprinkle all of them randomly around future posts as well.
If all goes well, which it already seems unlikely, This Christmas would be celebrated in India for me. On one hand, I am happy and excited to go back and hopefully get some rest and peace after more than 2 years. On the other, there really is no reason left for me to be back there except for my parents, which is disturbing, to say the least. So for the next post, whenever that happens, I'll have some photos to show of Chandigarh. Hopefully, the overpopulation and incompetence of politicians have not decimated the whole character of the city and what made it unique, but I highly doubt that. Because, well, India.
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| I missed the peak night of the Perseids shower, but on the upside, I FINALLY GOT A DECENT MILKYWAY PHOTO!!! |
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| It was still a lot of struggle because the skies aren't just dark enough near cities, and the lens choice was limited to either 10mm f\4.5 or 24mm f/2.8 on APS-C I'm still pleased with the result |
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| Probably the best money I spent Both on Camera and the Bike |
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| The beauty that is Eifel National Park. Along with a 40km bike ride through the forests in the summers, this is an outing to beat. |
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| Abandoned/old castles are plentiful in NRW and especially Rhineland Pfalz |
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| Practicing some portraiture with the help of my neighbour |
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| Einmal im Leben durch Wuppertal schweben Bucket List item - DONE! |
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| Munster |
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| German Amsterdam vibes - Munster |
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| Aasee - Munster |
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| Guess the place Random street photos like this are always my favorites |
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| Cologne main market along the Rhine - Always vibing |
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| One of my earlier attempts at light painting |
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| Always fun to play at f/1.8 |
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| Photo by Mr. Studtmann |
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| Also by Mr. Studtmann |
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| Random Wuppertal Strasse with Random Wuppertal Bürger (not burger) |
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| I really liked the unashamedly industrial look of some areas of Wuppertal |
Let's end this post here, again sticking to the self-imposed template. Along with a lot of new places and routes I discovered during this time, I discovered an equal, if not more, music and other artistic creations. Sadly for you, I cannot name all the artists in one go, because what fun is that? The work that has stood out the most for me during this time has to be Bo Burnham's Inside. Yes, that's also a hint right up there in the title of this post. Shame on you if you haven't found the pattern by this point.
Not only the Netflix special is funny and extremely entertaining, but it is also poignant and thought-provoking in a lot of areas. My favorite has to be "Shit" because that's how I have been feeling lately as well, and also "Welcome to the Internet", because now that I am an observer of social media and not an active participant for over one year, the amount of control it has on people, and the black-hole-esque nature of the internet, in general, is not lost on me. Bo's work has actively managed to make me more conscious of my Internet dependency and use, and I have been (rather unsuccessfully to be honest) trying to minimize the time I spend on the WWW being distracted.
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| I'm in this photo, and I like it. |
Final music suggestion to end this post on a funky note (see what I did there) -
I highly suggest you invest in some proper headphones, your music experience is elevated to the next level just by having slightly better audio equipment as compared to the weird wired earphones that are (were) included with phones. I got myself the Samson SR850 and I can highly recommend them for music listening sessions, where you just lie down, close your eyes, and flow with the music.
I hope I was able to keep your attention, and I wish you the very best for the upcoming year.
Comments are thoughts are always welcome, as usual. :)
Merry Christmas, Happy new year, and I will see you soon, dear reader.
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