ZED 2i positional tracking example shows the inaccurate trajectory result

We bought zed 2i and apply the project that needs position information. The project using Jetson TX2, so we set up the SDK for zetpack 4.5.0 and run the positional tracking example.

But we met problems because of inaccurate position measurement of zed 2i

First, positional tracking result shows like scale factor when we simply move forward and backward with the constant pose.(zed 2i moved with 4m, but positional tracking result display us with moving 2 meters)

Second, when we draw a rectangular trajectory outside, the trajectory result by zed 2i shows a non-recognizable trajectory like crushed and didn’t show a rectangular trajectory.

We set up the zed2i to see the forward environment and set parameters with below

// Setting initial parameters
init_params.camera_resolution = RESOLUTION::HD720;
init_params.DEPTH_MODE depth_mode_=DEPTH_MODE::ULTRA
init_params.camera_fps = 30;
init_params.coordinate_system = COORDINATE_SYSTEM::LEFT_HANDED_Z_UP;
init_params.coordinate_units = UNIT::METER; // Set units in meters

// Setting runetime parameters
runtime_params.confidence_threshold = 100;

// Setting coordinate 
POSITIONAL_TRACKING_STATE tracking_state = zed.getPosition(camera_pose, REFERENCE_FRAME::WORLD);

Even though we adjust ‘confidence_threshold’ with 50, 10, 5, the trajectory result shows the same as mentioned above.

We found the header file but we can’t find the algorithm that runs the positional tracking.
(Header file shows the role of function)

Can we know the reason that why the positional tracking shows inaccurate results?

Or are there any environment that positional tracking shows accurate result?

And… can we know the algorithm that is used in the positional tracking example?

We appreciate your help

Thank you

Hi @kym9508
can you please record an SVO file replicating the same conditions of the experiments that you performed and can you please share them with us (Google Drive, Dropbox, …) by writing an email to support@stereolabs.com?
In this way, you will open a ticket and you will get direct support to solve your issue.