My neighbor and I have been trying to do something similar to Tom Hastie's simulation (see here) but using only free software. Our goal is to get a closed-loop, all-software simulation using Flightgear as the flight simulation and SciLab as the autopilot stand-in. This allows for quick prototyping of your autopilot code without risking your aircraft. The best part, of course, is that it doesn't cost anything. :)
Brian (my neighbor and software guru) created a simple UDP server program to set up the connection between Fligthgear and SciLab. I wrote some prototype navigation/flight planning software in SciLab. When we run the simulation, we get flight data coming into SciLab and servo commands going back to Flightgear. However, there appears to be an approximately 2 second delay between when SciLab sends the command and the servos move in Flighgear. This causes the navigation algorithm to go unstable.
We have tried using both Flightgear versions 1.9 and 2.0.
I will try to upload some plots showing what we are getting when I get home.
Has anyone tried using Flightgear and SciLab together like this? Any thoughts on what we should try?
Yes, we were planning on sharing our code once we had this resolved. We were orginally trying to finish this for the "write DIY" T3 contest, so that tells you how long we have been working on this! Wives, kids, and jobs keep getting in the way! :P I was planning on sharing our flighplan and navigation code, as well as some tools I created for designing full-state feedback controllers using LQR.