On Sat, 2009-05-30 at 12:16 -0500, Curtis Olson wrote: > On Sat, May 30, 2009 at 12:02 PM, Vivian Meazza wrote: > I don’t see much of a problem with a suitable jumper. Making > it a ballistic object with drag and mass would be easy. But a > more realistic FDM … Hmmm > > > > An accurate FDM would be immensely complex considering all the > possible poses a human can achieve. But perhaps something simplistic > could be worked up using the arms and legs as control surfaces. My > focus right now is not so much getting accurate free fall dynamics, > but to get a nice jumper model and then just hack up some sort of > dynamics with approximately the right lift/drag ratio for someone is a > stable free fall pose.
I think a reasonable JSBsim fdm wouldn't be too hard, 2D drag tables for drag in different body positions, separate 2D table drag inputs for main-chute deployed and fouled. Same for backup chute... Cm, Cn, Cl functions for the 'chutes should swamp the body functions... use alpha 0 for standing upright, alpha -90 for head first... Could work... but... How do you control it? What joystick input does what? Before opening the 'chute different body positions affect drag, as well as pitching and yawing forces. Should viewing direction be considered head movement? http://www.dropzone.com/cgi-bin/safety/detail_page.cgi?ID=636 http://www.dropzone.com/cgi-bin/safety/detail_page.cgi?ID=696 Talks about using hip movement to properly steer the 'chute. http://www.dropzone.com/cgi-bin/safety/detail_page.cgi?ID=536 Mentions brakes, toggles, risers. Which button would do what? > The goal would be to get approximately the right fall rates and > timings so that there is training value in solving problems and > overcoming various combinations of faults with in a realistic time > frame. It's still only a very partial simulation but hopefully a step > better than just sitting around in a circle talking through various > scenarios. > > The next step would be to have a canopy that could be configured to > have various problems opening up and be able to draw that somehow from > the perspective of the sky diver, and perhaps have some appropriate > dyanmics for partially tangled or partially inflated chutes? > Obviously there's endless variabiltiy and high fidelity in all > respects would be crazy to try to achieve, but it would be interesting > to take a few small steps forward and see how far we can get. > > Best regards, > > Curt. ------------------------------------------------------------------------------ Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT is a gathering of tech-side developers & brand creativity professionals. Meet the minds behind Google Creative Lab, Visual Complexity, Processing, & iPhoneDevCamp as they present alongside digital heavyweights like Barbarian Group, R/GA, & Big Spaceship. http://p.sf.net/sfu/creativitycat-com _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
