When we had all the discussions about jerk, I forgot to mention a detail I picked up from Gerald Farin (when I was taking one of his CAGD classes), that when developing the early automated control systems for elevators that they did not consider limiting the jerk and it actually caused test subjects to get sick at their stomachs and hurl. IIRC, even the early systems limited not only the jerk, but higher order derivatives as well. Another cool things about the NURBS is that the smoothing can be be done to arbitrary order if there are enough degrees of freedom.
When I was fact checking to see if I could find a reference for the above, I did find the following reference: "Acceleraton and Jerk (rate of change of acceleration) are human comfort considerations. Practical limits are 4 ft/sec^2 acceleration and 8 ft/sec^3 for jerk. These are fairly aggressive but acceptable. Beyond these levels the car becomes an amusement ride. Use about 70% of these levels for a very smooth feel." <http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=00BzOQ> thought this might be of interest as an obtuse reference ;-) EBo -- ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
