Hi Neil, It looks like you guys are doing a pretty good job! Nice thrust test video. Were you using a scale to measure the thrust? Well, perhaps you will be lucky (or we were going about things wrong), but we found that you can't really tell how good your mechanical design is until you try to control it automatically. Once you get all the electronics/sensors, etc. on-board, the weight tends to be more than you had expected. More importantly, the structure we first tried tended to have vibrations in it which were in the same frequency range as expected vehicle dynamics, so we couldn't just filter them out. We had to go back and re-design the structure with tiny steel cables to tension it like a WWI biplane and make the structure stiff enough that the vibrations were negligible. The effect of the vibrations was to make the sensors move relative to the props and violate the simple rigid-body assumptions of our control model. Sean On Fri, Feb 11, 2011 at 12:01 AM, PICdude wrote: > Quoting Sean Breheny : > >> ... In my experience, as far as basic hovering and >> level flight go, the quadrotor is very challenging from a hardware >> perspective (i.e., making something light enough yet powerful enough >> to fly, making the structure stiff enough, etc.) but if you have done >> a solid job of the hardware, the control problem itself is fairly >> straightforward. > > We saw this as the easy part. =A0We're currently getting (for our > quad-copter project) 10.5 lbs of thrust with ~5lbs weight, so that's a > pretty significant payload. =A0The PID code has had us head-scratching > for a bit. > > http://www.veisystems.com/nose/quarc.html > > Cheers, > -Neil. > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .