"So I guess if I want to engage the team with any flight controls or IMU questions, there's no point posting to the OP forums anymore, is there :-)"

"What other (free) compilers have you tried for FPU support? Have you compared the ARM compiler (code size and performance) with other toolsets (such as Code Sourcery) - besides the h/w floating point performance, of course.
- Roy"

"@Yangbo,Sorry, I am not familiar enough with the Ardu code to tell you where those functions live, but I should think a simple search would be able to find them.@Igor (sorry so late with my reply)My experience is with full-size vehicles, not with…"

"Bill,

Now I see what you meant by "some interesting developments this weekend" :-)
Have you considered direct current control, instead of RPM control? What the flight controller cares about is thrust and torque, which should be proportional to…"

"Sorry to be nit-picky, but the Madgwick and Mahoney solutions are complementary filters, not Kalman filters. Are you saying you prefer the Madgwick filter to your EKF?

- Roy"

"@Marc S, Jack
The load position appears to be obtained from the VICON system, although the algorithm was developed using the two swing angles of the load.
http://marhes.ece.unm.edu/images/4/41/2012_ICRA_IPalunko_Swing_free...
- Roy"

"Bill,Great work, as always. I have some suggestions for improving the efficiency of the calculation:- Work in the body axes - that is, transform the GPS velocity into the body axes, instead of transforming the accelerometer reading into earth-axes.…"

"@ Jack - not so sure about that. Those robots are $4K apiece!"

"Looks very solid. What is the frame made of, and what are its dimensions?

- Roy"

"As Robert Lefebvre and I said earlier, it is not a good idea to integrate the rate feedback term as you have it shown. If you want to see what a good control loop architecture looks like, try this:…"

"Alex,
So, are you the "K" with Daniel providing the "Mel" of KMel Robotics? Can you give us any technical details about these vehicles? Are they for sale?

Thanks
Roy"

"@Anish - I've found in my limited experience that the papers are not as high quality as other more traditional sources, in general, but there are exceptions. You have to admire their open source spirit .@All,You may want to check out their sections…"

"Although both the current and the proposed architectures can be made to work, I think they both needlessly complicate the tuning process - which is complicated enough on its own. Also, the gains and some of the signals do not mean what you may think…"

"Hi Bill,It seems we are thinking along similar lines, although I am more focused on quaternions (and related parameterizations, at least for the moment) and you are sticking with rotation matricies. Once you know omega and delta_t, you can find the…"

"HI Bill,(sorry I'm so late in my reply)I created the figure you recommend, and I think I see what you are getting at. Let me see if we are on the same page:With a first order (linear) approximation to the kinematic integration soultion, we assume…"