Zero values in /visual_slam/tracking/odometry topic

Hi,

I am using the isaac_ros_vslam package with an Intel Realsense D455, integrated with the robot_localization package to get my robot localization.

Here, I’m facing the following problem: some covariance values of the /visual_slam/tracking/odometry topic are 0. This doesn’t happen all the time, but it happens quite often, making the EKF filter from robot_localization unstable.

As a workarund, I’m using the /visual_slam/tracking/vo_pose_covariance instead, as it’s value doesn’t have this problem.

Is this the expected behavior or is there some kind of issue?

This is an example of my /visual_slam/tracking/odometry topic


header:
stamp:
sec: 1718006137
nanosec: 72434082
frame_id: map
child_frame_id: base_link
pose:
pose:
position:
x: -0.18829065561294556
y: -0.7475811839103699
z: -0.14418889582157135
orientation:
x: 0.0009961834115019804
y: -0.03407587459564546
z: -0.05355979702336192
w: 0.997982553100213
covariance:

  • 0.0
  • 0.0
  • 0.0
  • 3.556602952334916e-20
  • -6.852714414421259e-19
  • 3.608248659603303e-19
  • 0.0
  • 0.0
  • 0.0
  • 5.659126527693679e-19
  • -3.7443462688228286e-18
  • -1.4718286660177989e-18
  • 0.0
  • 0.0
  • 0.0
  • -1.2553646994699983e-19
  • 1.0993890695959257e-18
  • 3.493265634971272e-18
  • 3.556602952334916e-20
  • 5.659126527693679e-19
  • -1.2553646994699983e-19
  • 7.932368483580105e-15
  • -6.72113073918508e-15
  • -8.448243274648833e-15
  • -6.852714414421259e-19
  • -3.7443462688228286e-18
  • 1.0993890695959257e-18
  • -6.721130739185079e-15
  • 1.8764574328284905e-14
  • 1.3875256018809103e-14
  • 3.608248659603303e-19
  • -1.4718286660177989e-18
  • 3.493265634971272e-18
  • -8.448243274648832e-15
  • 1.3875256018809105e-14
  • 2.5194641515562394e-14
    twist:
    twist:
    linear:
    x: 0.0
    y: 0.0
    z: 0.0
    angular:
    x: 7.583187826818249e-09
    y: -3.1724994084912666e-07
    z: -4.5952138011680034e-07
    covariance:
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 0.0
  • 5.6311578418487885e-14
  • -1.559435015746044e-14
  • -5.398157851896417e-14
  • 0.0
  • 0.0
  • 0.0
  • -1.559435015746044e-14
  • 2.510679075672562e-14
  • 3.039358842826922e-14
  • 0.0
  • 0.0
  • 0.0
  • -5.398157851896417e-14
  • 3.039358842826922e-14
  • 8.488513363067446e-14