<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[VOXL2 Camera Calibration fails and bad QVIO tracking]]></title><description><![CDATA[<h1><strong>Drone specification:</strong></h1>
<p dir="auto">I am currently using Starling 2 Max with</p>
<ul>
<li>Dual 4k &amp; Dual Tracking &amp; ToF (C29)</li>
<li>Microhard pMDDL2450 WiFi</li>
<li>Ghost Atto 2.4GHz</li>
<li><strong>SKU: MRB-D0012-4-V2-C29-M11-T9-K3</strong> (NOTE: This SKU is from the order receipt, which is different from the one shown when connected to the drone)</li>
</ul>
<pre><code>system-image: 1.8.06-M0054-14.1a-perf
kernel:       #1 SMP PREEMPT Wed Oct 22 04:13:18 UTC 2025 4.19.125
hw platform:  M0054
mach.var:     1.0.1
SKU:          MRB-D0012-4-V2-C29-T9-M22-X0
voxl-suite:   1.6.3

</code></pre>
<h1><strong>Cause:</strong></h1>
<p dir="auto">I recently flashed my VOXL2 board by following <a href="https://docs.modalai.com/voxl2-unbricking/" rel="nofollow ugc">"Unbricking your VOXL2" page</a>. This wipes all calibration files, of which I generated new ones by calibrating the drone again.</p>
<p dir="auto">However, I am having issue getting a successful camera calibration with the same error every time:</p>
<pre><code>Re-projection error reported by calibrateCamera: 1.26416
Calibration Failed
Max reprojection error: 0.60
This is most likely due to motion blur, please try again.
Exiting Cleanly
</code></pre>
<p dir="auto">I have tried to debug by following these suggestions below:<br />
<a href="https://forum.modalai.com/post/22010">https://forum.modalai.com/post/22010</a><br />
<a href="https://forum.modalai.com/post/22066">https://forum.modalai.com/post/22066</a><br />
<a href="https://forum.modalai.com/post/21909">https://forum.modalai.com/post/21909</a><br />
However,  none of these fixes the max reprojection error.</p>
<p dir="auto">Finally, I manually write the files:</p>
<ul>
<li>/data/modalai/opencv_tracking_front_intrinsics.yml</li>
<li>/data/modalai/opencv_tracking_down_intrinsics.yml</li>
</ul>
<p dir="auto">by using the camera matrix from the trial with smallest reprojection error (close to ~0.6).</p>
<h1><strong>Current Issue:</strong></h1>
<p dir="auto">My problem now is that, since the calibration files use bad camera matrices, the qvio tracking of the drone is inaccurate and drifts a lot. Here, I tested the front and downward camera by walking around in circle and returning the drone to the exact starting position. The result shows a lot of drift in both <em>qvio_extended</em> and <em>ov_extended</em><br />
<img src="/assets/uploads/files/1785878640350-screenshot-from-2026-08-04-17-23-29.png" alt="Screenshot from 2026-08-04 17-23-29.png" class=" img-fluid img-markdown" /></p>
<p dir="auto">My questions are:</p>
<ul>
<li>Could the reflash have altered camera driver versions, exposure/gain settings, or <code>voxl-camera-server</code> config from factory defaults?</li>
<li>Is there a way to compare my current per-camera intrinsics files against known-good factory defaults for the M0054 platform?</li>
<li>Are there other config I should try to change to aid the camera calibration process?</li>
<li>Is there any other open-source code that allows me to manually calibrate the camera?</li>
</ul>
<p dir="auto">Thank you for your time and help!</p>
]]></description><link>https://forum.modalai.com/topic/5363/voxl2-camera-calibration-fails-and-bad-qvio-tracking</link><generator>RSS for Node</generator><lastBuildDate>Thu, 06 Aug 2026 00:59:27 GMT</lastBuildDate><atom:link href="https://forum.modalai.com/topic/5363.rss" rel="self" type="application/rss+xml"/><pubDate>Tue, 04 Aug 2026 21:45:20 GMT</pubDate><ttl>60</ttl></channel></rss>