Powertrain control course

In conjunction with my other commitments this past semester, I decided to take a course on advanced powertrain control. The course covered, in a broad sense, the transmission of power from sources to loads in various mobile and stationary powertrain applications. Of course, one of the primary focuses of the course was applications to automotive powertrains, but we did look at many other applications, such as wind turbines and ships. The professor for the course came in with a lot of industry experience and was able to give us a fair amount of insight into what kind of control is actually used (notably in the automotive industry).

 Since there is a lot of current interest in hybrid vehicles, one of the pushes of the course was the hybrid electric vehicle. We discussed the overall powertrain architectures of these vehicles and how one would go about modeling them. We took a physics based approach to this course as opposed to data driven, and derived models for dynamics of the vehicle, ICEs, transmission, and the battery. For some in the class, these models would play an important role in coup de grace of the course, the final project. We also covered hydrogen fuel cell modeling for both supervisory control and servo level control, as well as wind turbine powertrains. Although we didn’t cover in depth control theory in this course (LMI controller synthesis, structure singular value robust analysis, passivity based controller, etc.), but rather focused on refining the basics (linear control theory, decoupling MIMO systems for single control, LQR optimal control).

 As I already mentioned, a major focus of this course was the final project. My partner and I took a vastly different take on the project when compared to our colleagues. Rather than modeling a vehicle, we decided to go with a ship based project as we both had research experience on ship based power systems. Our project was a feasibility analysis on a hybrid propulsion system for model ship. In conjunction with the traditional propeller propulsion, we coupled a Flettner rotor wind based system which operates using the Magnus effect. We optimized the system using dynamic programming given real world wind cycles, and it turned out that hybridizing the vessel could result in energy savings overall. In an attempt to validate the simulation results, we began to construct a Flettner rotor, but ended up scrapping the build due to time constraints. Overall, I’d recommend this class to anyone considering it. Though as a prerequisite, I’d recommend having a fairly strong grasp of basic control concepts.

On Heavy Rain

My girlfriend’s family recently bought a PS3 with a few games. One of the games that they eventually ended up purchasing was Heavy Rain. I had my reservations on initially hearing about the game. During my gaming history, I’ve never encountered a game were cut scenes are numerous and enjoyed the game! The newer Final Fantasy games were like this and always perturbed the hell out of me! I would find myself walking a few steps in the game and then I’d be loading then watching another cut scene. Of course, these comment perhaps paint me as a non-story driven gamer… however, that could not be further from the truth. I’ve always desired games with excellent story driven plot lines, such as Chrono Trigger or X, where the story is experienced as you play the game as to something inherently separate from the game itself. Heavy Rain is close to bridging that gap for me, and perhaps a couple of game iterations down the road, we’ll have perfect game in my eyes.


I don’t really want to reveal too much about the storyline of the game, as that is an intrinsic feature of the feel to the game and I don’t want to detract from it. The general plot is that you take control of four different characters in a mystery/crime genre plot. All of your choices and actions in the game propagate through the storyline and ultimately result in different possible endings. The controls are interesting. PS games have been adopting the interactive cut scenes where elements in a cut scene require reaction from the player through specific button combos, and Heavy Rain continues down this path. In this way, you feel more connected to the cut scene. However, the third person game play feels force most of the time, and the camera angles (like most 3d third person games) can at times become aggravating. I’ve always wondered why so many developers have such animosity towards the first person camera mode. Not only do you feel more connected, but you also eliminate the nuisance of idiotic camera angles which detract from the gaming experience. Had the game been first player during the standard game mode, I actually wouldn’t have much negative to remark about the game!

Overall, watching the game makes me wish that I had a PS3 to experience more of the varied endings of the game. Perhaps one day, it’ll be released to the PC where all games should be played anyways!

Qualified!

As of a few weeks ago, I can officially refer to myself as a PhD candidate as opposed to the more lackluster title of PhD student. It is set in stone now, I’ve passed my qualifying exams and I’m now ready to move on to the meat of the doctoral degree… proposing research and then the final defense! The whole process took a good five months to complete in its entirety. Beginning with the oral exams, which involves complete knowledge of undergraduate mechanical engineering curriculum, we finished out with a mini-research project which lasted another couple of months. I spent a good chunk of the summer solidifying engineering concepts in my mind. A group of several of us were taking the exam at the end of the summer and thus we spent many days and nights reviewing concepts and discussing problems. From nearly relearning some concepts in thermal fluid systems, to going crazy with three dimensional multi-body dynamical equations, I actually felt like the review of engineering concepts was beneficial to me in the long run. I ultimately passed the exam and then moved on to the research portion.

The research portion was more of an agonizing experience in my opinion than the oral exam. Even though there was an initial intimidation factor involve with the oral examination, working problems on the board in front of the faculty, once the momentum of the exam built up, by Netwon’s first law, I felt unstoppable! On the other hand, the research was a drawn out process of confusion. One of the main aggravating factors of the research portion of the exam is the isolation of the project. For any other research I had ever conducted prior to the qualifying exams, I was able to bounce ideas off of colleges and faculty members. However, for the research portion, we were required to work completely solo on this exam for the entire two month period. A sense of worry instilled itself in me during this process due to my aggrandized views of faculty expectations. I doubted my research project’s depth (turns out that a simple example is ideal, no need to dabble in the complex details for such a short project), and I fretted that my overall results were not addressing my hypothesis to the extent that all the members of my committee desired (turns out that I nailed it pretty much spot on…). All my doubts were abated, and I found out, to my delight, that my work was fine, and all the doubting was for nothing!

My word of advice to all those that will follow in my footsteps is to not over-analyze everything, since that only leads to unnecessary worries. Focus on your studies for the oral portion of the exam, and know the basics like the back of your hand. For the research portion, select a manageable project and the faculty will help you flesh out the details of the hypothesis. Then ensure that you know your references inside and out, and don’t quote anything without knowing for sure if it is true. The faculty will ask you where you found your claims and how (even if it is a journal paper) you know for certain that the results are sound. Essentially, use your best judgment and don’t report anything that you do not understand! If you follow that basic advice and can stomach the five months that this all takes, congrats… you’re on your way to becoming a PhD candidate too!