<?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[AprilTag Localization not affecting static coordinate system]]></title><description><![CDATA[<p dir="auto">I am trying to get AprilTag localization working on the Starling 2 drone but I cannot get the fixed coordinate system to change based on the apriltag. I am able to detect it correctly, but relocalization does not work.</p>
<p dir="auto">Here are relevant configuration files, I mainly followed the example <a href="https://docs.modalai.com/voxl-vision-hub-apriltag-relocalization/" rel="nofollow ugc">link</a>.</p>
<p dir="auto">voxl-tag-detector.conf</p>
<pre><code>/**
 * This file contains configuration parameters for voxl-tag-detector.
 * You can specify up to 3 cameras to do detection on simultaneously.
 * For the stereo camera pair, only the left camera is used.
 */
{
	"detector_0":	{
		"enable":	true,
		"input_pipe":	"tracking_front",
		"en_fast_mode":	true,
		"n_threads":	1,
		"en_undistortion":	true,
		"undistort_scale":	0.600000023841858,
		"overlay_name":	"tracking_tag_overlay",
		"lens_cal_file":	"/data/modalai/opencv_tracking_front_intrinsics.yml",
		"skip_n_frames":	5
	}
}
</code></pre>
<p dir="auto">tag_locations.conf</p>
<pre><code>{
        "locations":    [{
                        "id":   0,
                        "name": "landing-pad",
                        "loc_type":     "fixed",
                        "size_m":       0.17145,
                        "T_tag_wrt_fixed":      [0, 0, 0],
                        "R_tag_to_fixed":       &lsqb;&lsqb;0, -1, 0], [1, 0, 0], [0, 0, 1&rsqb;&rsqb;
                }],
        "default_size_m": 0.17145 //  0.40000000596046448
}
</code></pre>
<p dir="auto">in voxl-vision-hub.conf I have</p>
<pre><code>"en_tag_fixed_frame": true,
"en_transform_mavlink_pos_setpoints_from_fixed_frame": true
</code></pre>
<p dir="auto">When I run</p>
<pre><code>voxl-vision-hub -l
</code></pre>
<p dir="auto">I am able to see the tags position update as it moves.</p>
<p dir="auto">When I run</p>
<pre><code>voxl-vision-hub -p
</code></pre>
<p dir="auto">I can see the local_wrt_fixed change when the drone moves, but not when the tag moves. I would expect the local_wrt_fixed to also change with the tag moving since it is set to be [0,0,0].</p>
<p dir="auto">I also often get a "WARNING, apriltag roll/pitch out of bounds", which appears to be a common issue.</p>
<p dir="auto">Is there a configuration error I am missing or some way I can get the relocalization system to work?</p>
]]></description><link>https://forum.modalai.com/topic/5197/apriltag-localization-not-affecting-static-coordinate-system</link><generator>RSS for Node</generator><lastBuildDate>Wed, 06 May 2026 19:44:11 GMT</lastBuildDate><atom:link href="https://forum.modalai.com/topic/5197.rss" rel="self" type="application/rss+xml"/><pubDate>Wed, 06 May 2026 15:09:15 GMT</pubDate><ttl>60</ttl></channel></rss>