About the schmidt function during initialization process

[mingrenzhu]

Hi,
The rotation matrix between gravity direction and imu is calculated using stationary imu measurements. The code is implemented as follows:

open_vins/ov_init/src/utils/helper.h

Line 138 in 98c5525

static void gram_schmidt(const Eigen::Vector3d &gravity_inI, Eigen::Matrix3d &R_GtoI) {

Seem to have a problem with following code:
if (fabs(inner1) >= fabs(inner2))
In the extreme case e_1 is parallel to z_axis, then if the following operation is performed, so the cross product is zero, and the x_axis vector is not computed
x_axis = z_axis.cross(e_1);
So I think the correct operation to do is to modify the "if judgment" to be less than or equal, as following
if (fabs(inner1) <= fabs(inner2))

Looking forward to your reply， thanks !

[goldbattle]

Yep, looks like this would fail in that case. Thanks for the report.