> At 11:48 PM 5/1/03 , you wrote: >I'm not an engineer and will have to defer to those who can comment on this >in a more informed way, but your reference to the key doesn't change my >point. Movement of the key is being resisted by a variety of factors the >would eliminate any significant effects of momentum in key travel, or so it >seems to me. > >David Love >davidlovepianos@earthlink.net As I see it this will be one of the problems that Stephen Birkett (or any other contenders) faces in making a dynamic model of an action. What input are you going to use? Does the player push down with constant force? With constant velocity? With constant acceleration? Does he push down with more force initially to break the static friction and then back off to a lower force? Does he attempt to rapidly accelerate the key in the first part of the movement and then maintain a constant velocity for the rest of the movement? Etc, etc. I'm sure you can imagine other various scenarios. And it probably changes depending on whether the pianist is playing legato or staccato, soft or loud, fast or slow, etc. This information is the input to a model, not the output from it. The model isn't going to tell you how the pianist is pushing down the key. If you tell the model how the pianist is pushing down the key it will give you some idea of how the action is responding to the input. So you first have to do a rather elaborate study to determine in what manner pianists push down keys. Did I hear someone say Ph.D. thesis? Phil F
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