Sports Engineering
I am a proud member of the International Sports Engineering Association (ISEA) which is a group of professors, students, and industry all over the world that analyze and design innovated equipment for the use of sports. This association allows me to combine my two passions of sport and engineering and to pursue a career in which I can impact the games I love through engineering.
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I was fortunate enough to attend the 9th Annual ISEA Conference in Lowell, Ma in the summer of 2012 where I made connections with researcher, innovators, and industry all over the world. This week long Conference of over 50 seminars educating me in numerous areas of sports including: the use of high speed cameras and software , measurement and instrumentation, innovation in design, simulation and modeling and more.
Sponsoring my trip to the ISEA Conference was UC Davis Professor and Sports Biomechanics Laboratory Director, former ISEA President and 2012 recipient of the top Sports Engineer Award, my Mentor and friend, Mont Hubbard. I am very fortunate that Professor Hubbard has taken me under his wing and opened my eyes to a career that I love. We share a passion for sports and engineering, and have sought out to achieve a very complicated baseball research project. In 2003, Hubbard, along with graduate student Gregory Sawicki and Cambridge University colleague William Stronge co-authored and published the paper "How to Hit Homeruns". That paper looked at the optimal swing parameters for three pitches: a fastball, a curveball, and a knuckleball based on a rigid-body model. what this means is that this mathematical simulation took the baseball bat and ball to be infinitely stiff with no flexing or deformation what-so-ever. This model was a simpler assumption that brought about some fascinating results like with the optimal swing, a curveball can actually be hit further than a fastball because of the aerodynamic properties due to the different spin of the ball. The goal of our new project is to take the model a step further and do the same analysis with large deformation characteristics in the ball.
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The mathematics behind the contact of a baseball bat and ball are very complicated as you can imagine looking at the picture to the right. There are serious deformations in the baseball that have a big effects on the resulting hit of the ball.
Unlike the old rigid-body model, there are now three stages of contact. The first phase of contact is the initial slip phase. To understand this stage, you must recognize that the ball has some initial spin from being thrown (unless it is a perfect knuckleball). The incoming ball makes contact with the bat and the spin of the ball slips on the surface of the bat as it slows to a stop. Simultaneously, the ball is deforming around the bat. The moment when the ball stops slipping (or spinning on the bat) and the ball is at its maximum deformation, is the next stage of contact. This stage is called the stick phase and is shown in the picture to the right. The last stage is the opposite of the first where the ball starts to slip once again, but in the reverse direction, and release from its deformed shape to its normal shape until losing contact with the bat. Keep in mind that this three stage contact period occurs in only one millisecond (1/1000 of a second) with each individual stage governing their own unique characteristic equations.
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So now, with the new contact model involving these large deformation calculations looks to be implemented to the same optimization program for a baseball swing, still looking at three different pitches: a fastball, a curveball, and a knuckleball. The results are to come...