Plane: fixed home reset alt bias

this fixes a bug in the set of home alt while disarmed. The set had a
circular dependency which could cause a large bias to build up between
home alt and gps alt due to small fluctuations in barometer data

Thanks to Nick Allen for spotting this
This commit is contained in:
Andrew Tridgell 2019-06-28 14:11:38 +10:00
parent a38b030c41
commit ff08de033e
1 changed files with 7 additions and 1 deletions

View File

@ -122,7 +122,13 @@ void Plane::update_home()
}
if (ahrs.home_is_set() && !ahrs.home_is_locked()) {
Location loc;
if(ahrs.get_position(loc)) {
if(ahrs.get_position(loc) && gps.status() >= AP_GPS::GPS_OK_FIX_3D) {
// we take the altitude directly from the GPS as we are
// about to reset the baro calibration. We can't use AHRS
// altitude or we can end up perpetuating a bias in
// altitude, as AHRS alt depends on home alt, which means
// we would have a circular dependency
loc.alt = gps.location().alt;
if (!AP::ahrs().set_home(loc)) {
// silently fail
}