On Sunday 25 Sep 2005 09:12, Roy Vegard Ovesen wrote: > On Wednesday 21 September 2005 15:23, Lee Elliott wrote: > > The agl data can be pretty spiky due to terrain/scenery > > artifacts and 3d buildings/structures and using a moving > > average filter here reduces the influence of the spikes they > > produce.. > > Have you tried the noise-spike filter?
Yep - that was the first thing that came to mind but I still had problems when flying over buildings and the occasional terrain intersection. It's mostly because I wanted to use high gains and output values and while the noise-spike filter seems to clip the value at the set limit the initial rate of change in the data is unaffected and the following 2nd stage PID controller still seems to see a spike. I also hit a problem using a moving-average filter on the nav1 heading error data and found that there seemed to be a permanent offset in the output. Re-loading the autopilot seemed to fix the offset and the filter then worked normally. I guessed that the problem might have been been due to the filter starting to run before the nav1 data was ready so I stuck a simple noise-spike filter in front of the moving-average filter and this seemed to cure it. This is in the MiG-15bis that I've just e-mailed to Curt. I've also tried a couple of other things in the MiG15's A/P - I've used common 2nd stage controllers for most of the altitude and heading mode 1st stage controllers. Apart from reducing the number of controllers, it seems to improve the transitions between different modes. LeeE _______________________________________________ Flightgear-devel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
