Kevin Reilly's Posts (1)

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Odd roll behavior with MatrixNav?

Hi all, I'm new here. I'm trying to get an IMU based UAV up and running to do some research into higher level mission planning. I decided to go with William Premerlani's UAV DevBoard, but I'm having some problems with the MatrixNav firmware. I'm using a Parkzone Radian powered sailplane (3 ch, no ailerons).Right now I'm running without a GPS (it died in the last crash I think), but I mainly want to verify that pitch stabilization works with our airplane. So, the only modifications I've made were to turn on pitch stabilization in all modes (auto and RTL) and skip the GPS initialization.The problem I'm noticing has to do with pitch compensation during roll. My understanding is that a small amount of up elevator is required during turns in order to maintain altitude. When testing on the ground (just holding the airplane in my hand) I can pitch the plane up and down and the elevator moves correctly to compensate. When I roll the airplane to the left (to simulate a left turn) the elevator also compensates correctly by pitching up slightly to maintain altitude. However when I roll to the right, the elevator tries to pitch down, the exact opposite of what it should be doing. This actually caused two pretty bad crashes before I realized what the problem was, oh well.Has anyone else noticed or dealt with this behavior before? any ideas or suggestions would of course be very much appreciated. Thanks!
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