/// return true if the compass should be used for yaw calculations
bool
Compass::use_for_yaw(void) const
{
uint8_t prim = get_primary();
return healthy(prim) && use_for_yaw(prim);
}
bool Compass::consistent() const
{
Vector3f primary_mag_field = get_field();
Vector3f primary_mag_field_norm;
if (!primary_mag_field.is_zero()) {
primary_mag_field_norm = primary_mag_field.normalized();
} else {
return false;
}
Vector2f primary_mag_field_xy = Vector2f(primary_mag_field.x,primary_mag_field.y);
Vector2f primary_mag_field_xy_norm;
if (!primary_mag_field_xy.is_zero()) {
primary_mag_field_xy_norm = primary_mag_field_xy.normalized();
} else {
return false;
}
for (uint8_t i=0; i<get_count(); i++) {
if (use_for_yaw(i)) {
Vector3f mag_field = get_field(i);
Vector3f mag_field_norm;
if (!mag_field.is_zero()) {
mag_field_norm = mag_field.normalized();
} else {
return false;
}
Vector2f mag_field_xy = Vector2f(mag_field.x,mag_field.y);
Vector2f mag_field_xy_norm;
if (!mag_field_xy.is_zero()) {
mag_field_xy_norm = mag_field_xy.normalized();
} else {
return false;
}
float xyz_ang_diff = acosf(constrain_float(mag_field_norm * primary_mag_field_norm,-1.0f,1.0f));
float xy_ang_diff = acosf(constrain_float(mag_field_xy_norm*primary_mag_field_xy_norm,-1.0f,1.0f));
float xy_len_diff = (primary_mag_field_xy-mag_field_xy).length();
// check for gross misalignment on all axes
bool xyz_ang_diff_large = xyz_ang_diff > AP_COMPASS_MAX_XYZ_ANG_DIFF;
// check for an unacceptable angle difference on the xy plane
bool xy_ang_diff_large = xy_ang_diff > AP_COMPASS_MAX_XY_ANG_DIFF;
// check for an unacceptable length difference on the xy plane
bool xy_length_diff_large = xy_len_diff > AP_COMPASS_MAX_XY_LENGTH_DIFF;
// check for inconsistency in the XY plane
if (xyz_ang_diff_large || xy_ang_diff_large || xy_length_diff_large) {
return false;
}
}
}
return true;
}