<?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[GPS-denied Navigation (VIO)]]></title><description><![CDATA[Questions about developing software on the products]]></description><link>https://forum.modalai.com/category/19</link><generator>RSS for Node</generator><lastBuildDate>Thu, 09 Jul 2026 18:37:35 GMT</lastBuildDate><atom:link href="https://forum.modalai.com/category/19.rss" rel="self" type="application/rss+xml"/><pubDate>Fri, 22 May 2026 16:48:04 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[Visual position estimate and offboard control]]></title><description><![CDATA[@bschulzhf PX4 will only correct incoming messages. Something external will have to also run TIMESYNC with PX4 to estimate the offset and correct and incoming PX4 message timestamps that it wants to align. voxl-mavlink-server does this for a few messages.
]]></description><link>https://forum.modalai.com/topic/5217/visual-position-estimate-and-offboard-control</link><guid isPermaLink="true">https://forum.modalai.com/topic/5217/visual-position-estimate-and-offboard-control</guid><dc:creator><![CDATA[Eric Katzfey]]></dc:creator><pubDate>Fri, 22 May 2026 16:48:04 GMT</pubDate></item><item><title><![CDATA[Two-camera VIO non-functional in voxl-open-vins-server 0.6.0 (SDK 1.6.3)]]></title><description><![CDATA[I have uploaded the latest ar0144 drivers with fsin versions for all camera slots here : https://storage.googleapis.com/modalai_public/temp/ar0144/ar0144_drivers_20260402.zip
There are two additional files (inside the zip), which you should copy to /usr/lib/camera  to make sure you have the latest updates:

com.qti.sensor.ar0144.so -- contains functions for exposure / gain control (we recently made some improvements to make gain control smoother)
com.qti.tuned.default.bin -- fixed gain scaling so that min gain (1.0x analog gain) is equal to 100 in the HAL3 gain units, not 54 (and the max gain will be 29.6 = 29600 for AR0144) -- you can also double check this using voxl-camera-server -l and update the min/max gain settings in your voxl-camera-server.conf to make sure you are using the full range.

My colleague will follow up with a diagram for locations of the DNI resistors that need to be installed to enable sync signal for camera slots 1 and 3 (0402 0-ohm resistor)
Alex
]]></description><link>https://forum.modalai.com/topic/5148/two-camera-vio-non-functional-in-voxl-open-vins-server-0-6-0-sdk-1-6-3</link><guid isPermaLink="true">https://forum.modalai.com/topic/5148/two-camera-vio-non-functional-in-voxl-open-vins-server-0-6-0-sdk-1-6-3</guid><dc:creator><![CDATA[Alex Kushleyev]]></dc:creator><pubDate>Thu, 02 Apr 2026 12:28:11 GMT</pubDate></item><item><title><![CDATA[OpenVINS issue]]></title><description><![CDATA[@zauberflote1 I am no longer having this issue. I have been flying with OpenVins for some time, and I was sometimes seeing drift in the vio estimate, and I was wondering what are the best configs to use. for vio_cams.conf and voxl-open-vins-server.conf?
]]></description><link>https://forum.modalai.com/topic/5040/openvins-issue</link><guid isPermaLink="true">https://forum.modalai.com/topic/5040/openvins-issue</guid><dc:creator><![CDATA[Nitin Varma Vegesna]]></dc:creator><pubDate>Sun, 08 Feb 2026 08:06:27 GMT</pubDate></item><item><title><![CDATA[No ov_overlay in portal]]></title><description><![CDATA[@zauberflote1
alright, thanks for your help!
]]></description><link>https://forum.modalai.com/topic/4991/no-ov_overlay-in-portal</link><guid isPermaLink="true">https://forum.modalai.com/topic/4991/no-ov_overlay-in-portal</guid><dc:creator><![CDATA[Dronodev]]></dc:creator><pubDate>Sun, 18 Jan 2026 01:01:45 GMT</pubDate></item><item><title><![CDATA[Open-VINS Mask File Location]]></title><description><![CDATA[@zauberflote1 ok, thank you!
I will try to implement the mask as in VoxlCam.
Regards,
Jacob
]]></description><link>https://forum.modalai.com/topic/4944/open-vins-mask-file-location</link><guid isPermaLink="true">https://forum.modalai.com/topic/4944/open-vins-mask-file-location</guid><dc:creator><![CDATA[jakkkkobo]]></dc:creator><pubDate>Sun, 21 Dec 2025 19:19:56 GMT</pubDate></item><item><title><![CDATA[Request: Add Flight Deck 2 YAML Configurations for OpenVINS Testing]]></title><link>https://forum.modalai.com/topic/4918/request-add-flight-deck-2-yaml-configurations-for-openvins-testing</link><guid isPermaLink="true">https://forum.modalai.com/topic/4918/request-add-flight-deck-2-yaml-configurations-for-openvins-testing</guid><pubDate>Thu, 11 Dec 2025 07:57:36 GMT</pubDate></item><item><title><![CDATA[Running QVIO on a hires camera]]></title><description><![CDATA[@Rowan-Dempster , Thanks for the update!
On my end, I did not get a chance to enable MISP pipeline (normalization in particular) to run offline. Let me double check something with you - would you want to load a log with raw10 and resize + generate the normalized image (of a different size) or just keep the same size as input?
Since you have the basic rolling shutter QVIO working, it would be interesting to see how that compares to the AR0144 QVIO from the same data set. Any details you would like to share? (only if you want to) 
Regarding playback results from QVIO output not being exactly repeatable -- " no deterministic mechanism to ensure that voxl-qvio-server initializes using the same camera frame" -- what do you mean by that? if you start QVIO and start feeding the frames + imu data from voxl-replay, the data should arrive into QVIO repeatably and QVIO should initialize on the same frame - after the initialization conditions have been satisfied.
If I remember correctly the way QVIO app works is that it may hold the frame until all the IMU data for that frame has arrived and then pushes the frame into the QVIO algorithm. If you push the frame before pushing all the IMU data, then the algorithm will still process the frame but it wont have the IMU data for the whole duration of the frame capture.
The frame capture duration for global shutter cameras is simple :

start = start of exposure
end = end of exposure = start of exposure + exposure time
(i believe it is common to assign a timestamp which is equal to the center of exposure, which is between the start and end timestamps).
center of exposure = start of exposure + (exposure time)/2

In order to find the center of exposure for rolling shutter camera, you need to use the following formula, as used in our EIS implementation in MISP:
int64_t center_of_exposure_ns = start_of_exposure_ns + (exposure_time_ns + readout_time_ns)/2;

In any case, this would be something to double check.. also i don't know how far your trajectories are from run to run.
Another tip: since you don't have ground truth in your data, it helps to start and end your data collection in exactly the same spot and orientation, so you can use the end position drift as a good metric (ground truth).
Alex
]]></description><link>https://forum.modalai.com/topic/4900/running-qvio-on-a-hires-camera</link><guid isPermaLink="true">https://forum.modalai.com/topic/4900/running-qvio-on-a-hires-camera</guid><dc:creator><![CDATA[Alex Kushleyev]]></dc:creator><pubDate>Tue, 02 Dec 2025 22:31:10 GMT</pubDate></item><item><title><![CDATA[Migrating from QVIO to OpenVINS (SDK1.6)]]></title><description><![CDATA[To clarify, our current platforms are shipped with voxl-open-vins-server as the default VINS solution; however, QVIO is still available (SDK 1.6.2).
]]></description><link>https://forum.modalai.com/topic/4894/migrating-from-qvio-to-openvins-sdk1-6</link><guid isPermaLink="true">https://forum.modalai.com/topic/4894/migrating-from-qvio-to-openvins-sdk1-6</guid><dc:creator><![CDATA[zauberflote1]]></dc:creator><pubDate>Wed, 26 Nov 2025 22:45:09 GMT</pubDate></item><item><title><![CDATA[Missing ov_overlay]]></title><description><![CDATA[@tom  Thank you for your answer!
Unfortunately the overlay does not appear, even when the drone is armed. We are using Starling 2 drones with SDK 1.6.2.
Also in the voxl-open-vins-server.conf we can't find a setting for something related to the overlay.
Do you have any ideas what we can try to see the ov_overlay again?
Thank you in advance!
]]></description><link>https://forum.modalai.com/topic/4887/missing-ov_overlay</link><guid isPermaLink="true">https://forum.modalai.com/topic/4887/missing-ov_overlay</guid><dc:creator><![CDATA[saegsali]]></dc:creator><pubDate>Mon, 24 Nov 2025 10:28:59 GMT</pubDate></item><item><title><![CDATA[How to Enable OpenVINS to Start Feature Tracking on Boot for Full Autonomous Use-Case]]></title><description><![CDATA[@wilkinsaf  Do you happen to have any experience with this?
]]></description><link>https://forum.modalai.com/topic/4847/how-to-enable-openvins-to-start-feature-tracking-on-boot-for-full-autonomous-use-case</link><guid isPermaLink="true">https://forum.modalai.com/topic/4847/how-to-enable-openvins-to-start-feature-tracking-on-boot-for-full-autonomous-use-case</guid><dc:creator><![CDATA[Michael Baldwin]]></dc:creator><pubDate>Thu, 30 Oct 2025 22:32:41 GMT</pubDate></item><item><title><![CDATA[setting up VIO on VOXL2 (custom frame)]]></title><description><![CDATA[@psafi Here are the steps I am taking for camera calibration:
1- run the following command:
voxl-calibrate-camera tracking_down -f -s 6x9 -l 0.022
2- look at the overlay in portal (see the screenshot below)
3- calibration process is not progressing automatically even though it seems like the checkerboard is detected
[image: 1760465700997-e47c8511-c92f-4ce7-83f6-49d59dd89e7d-screenshot-from-2025-10-14-11-14-52.png]
]]></description><link>https://forum.modalai.com/topic/4768/setting-up-vio-on-voxl2-custom-frame</link><guid isPermaLink="true">https://forum.modalai.com/topic/4768/setting-up-vio-on-voxl2-custom-frame</guid><dc:creator><![CDATA[psafi]]></dc:creator><pubDate>Wed, 24 Sep 2025 21:28:58 GMT</pubDate></item><item><title><![CDATA[VIO drifting when using TFlite Server]]></title><description><![CDATA[@Moderator thank you for the recommendation. I will try out this.
]]></description><link>https://forum.modalai.com/topic/4744/vio-drifting-when-using-tflite-server</link><guid isPermaLink="true">https://forum.modalai.com/topic/4744/vio-drifting-when-using-tflite-server</guid><dc:creator><![CDATA[Ege Yüceel]]></dc:creator><pubDate>Mon, 15 Sep 2025 23:03:56 GMT</pubDate></item><item><title><![CDATA[Calibraation files not saving and camera intrinsics failing]]></title><description><![CDATA[@Moderator Even I am facing the same issue. Did everything as per the instructions on the official website. But unable to calibrate the stereo front. I was able to calibrate stereo back though. I have attached the error along for your reference.
]]></description><link>https://forum.modalai.com/topic/4682/calibraation-files-not-saving-and-camera-intrinsics-failing</link><guid isPermaLink="true">https://forum.modalai.com/topic/4682/calibraation-files-not-saving-and-camera-intrinsics-failing</guid><dc:creator><![CDATA[Manoj Kashyap]]></dc:creator><pubDate>Fri, 15 Aug 2025 16:00:35 GMT</pubDate></item><item><title><![CDATA[How to start with VIO?]]></title><link>https://forum.modalai.com/topic/4645/how-to-start-with-vio</link><guid isPermaLink="true">https://forum.modalai.com/topic/4645/how-to-start-with-vio</guid><pubDate>Sat, 02 Aug 2025 07:31:53 GMT</pubDate></item><item><title><![CDATA[QVIO unstable flight. Please help!]]></title><description><![CDATA[@Daniel-Rincon have you looked through the troubleshooting guide? https://docs.modalai.com/flying-with-vio/#troubleshooting-vio
Usually looking at the ovins-overlay in voxl-portal offers good insight
The common issues are vibration is too high, the extrinsics are incorrect or there are not enough features to track in the environment
]]></description><link>https://forum.modalai.com/topic/4626/qvio-unstable-flight-please-help</link><guid isPermaLink="true">https://forum.modalai.com/topic/4626/qvio-unstable-flight-please-help</guid><dc:creator><![CDATA[Moderator]]></dc:creator><pubDate>Wed, 23 Jul 2025 16:13:20 GMT</pubDate></item><item><title><![CDATA[Sendor suit getting stalled]]></title><description><![CDATA[@Alex-Kushleyev Thank you for reverting, I will check this out and get back to you
]]></description><link>https://forum.modalai.com/topic/4467/sendor-suit-getting-stalled</link><guid isPermaLink="true">https://forum.modalai.com/topic/4467/sendor-suit-getting-stalled</guid><dc:creator><![CDATA[Jetson Nano]]></dc:creator><pubDate>Thu, 29 May 2025 13:41:17 GMT</pubDate></item><item><title><![CDATA[Sensor Fusion Question w&#x2F; GPS, VIO, and downward distance sensor on Starling 2]]></title><description><![CDATA[@shawn_ricardo Hi!
To my understanding EKF2_EV_CTRL 15--&gt;13 only remove EV from pos_z estimation, so it should be ok to do that if the range sensor is active. However, I did revert all parameters to the default settings (matching the VOXL-SDK definitions).
As my attempts to integrate the range-sensor data in altitude estimation did not seem to succeed, I decided to try and integrate the range-sensor in the VIO solution.
I created a version of the voxl-qvio-server in which pos_z estimation from VIO is replaced by the equivalent value based on the rangefinder:
s.T_imu_wrt_vio[2] =  - down_range_m;
This seem to work better, however it is a workaround and not a full solution. My current experiments are performed in low altitude (~40-90 cm), so I am not concerned with the limited range of the rangefinder sensor.
I'm not sure what is the current implemented behaviour when EV estimation is not good, there should be some fall-back relying on the range sensor and imu. From my short experience with such cases of poor EV estimation mid-flight, the drone just crushes or jump to the ceiling with no control.
Any suggestions or further explanations will be much appreciated. Thank you
]]></description><link>https://forum.modalai.com/topic/4440/sensor-fusion-question-w-gps-vio-and-downward-distance-sensor-on-starling-2</link><guid isPermaLink="true">https://forum.modalai.com/topic/4440/sensor-fusion-question-w-gps-vio-and-downward-distance-sensor-on-starling-2</guid><dc:creator><![CDATA[Meytal Lempel]]></dc:creator><pubDate>Mon, 19 May 2025 17:27:36 GMT</pubDate></item><item><title><![CDATA[VIO in dark environments]]></title><description><![CDATA[@Alex-Kushleyev Thank you very much!
]]></description><link>https://forum.modalai.com/topic/4324/vio-in-dark-environments</link><guid isPermaLink="true">https://forum.modalai.com/topic/4324/vio-in-dark-environments</guid><dc:creator><![CDATA[Dronodev]]></dc:creator><pubDate>Mon, 07 Apr 2025 21:14:30 GMT</pubDate></item><item><title><![CDATA[Problems in resetting voxl-open-vins-server]]></title><description><![CDATA[@zauberflote1 Hi,
So, it’s almost impossible for OpenVINS’ VIO to successfully reset while the drone is in flight if even a simple hand movement (which I always tried to do gently) is enough to prevent proper reinitialization, right?
What I used to do to break the VIO was cover the camera, wait for x, y, and z to return to zero, and then uncover it.
As for the test environment, it's rich in features, so I don't think that's the issue.
I increased the publish and tracking frequency because I wanted to ensure the VIO was "responsive," and with two or three cameras, I consistently achieved reliable results.
]]></description><link>https://forum.modalai.com/topic/4292/problems-in-resetting-voxl-open-vins-server</link><guid isPermaLink="true">https://forum.modalai.com/topic/4292/problems-in-resetting-voxl-open-vins-server</guid><dc:creator><![CDATA[Marco Spangaro]]></dc:creator><pubDate>Wed, 26 Mar 2025 14:58:50 GMT</pubDate></item><item><title><![CDATA[OV with External Autopilot]]></title><description><![CDATA[@SKA What pipes do you see listed in /run/mpa? If you run the command voxl-inspect-vio does it show that VIO is running okay?
]]></description><link>https://forum.modalai.com/topic/4257/ov-with-external-autopilot</link><guid isPermaLink="true">https://forum.modalai.com/topic/4257/ov-with-external-autopilot</guid><dc:creator><![CDATA[Eric Katzfey]]></dc:creator><pubDate>Thu, 13 Mar 2025 21:27:07 GMT</pubDate></item><item><title><![CDATA[VIO Features not updating &#x2F; VIO not estimating correctly]]></title><link>https://forum.modalai.com/topic/4243/vio-features-not-updating-vio-not-estimating-correctly</link><guid isPermaLink="true">https://forum.modalai.com/topic/4243/vio-features-not-updating-vio-not-estimating-correctly</guid><pubDate>Fri, 07 Mar 2025 23:15:26 GMT</pubDate></item><item><title><![CDATA[OpenVINS Reinitializing Issue]]></title><description><![CDATA[@SKA Yes, VFT is actually deprecated in 1.4.1
Please replace your ovins config with this and give it a try:
]]></description><link>https://forum.modalai.com/topic/4159/openvins-reinitializing-issue</link><guid isPermaLink="true">https://forum.modalai.com/topic/4159/openvins-reinitializing-issue</guid><dc:creator><![CDATA[Cliff Wong]]></dc:creator><pubDate>Fri, 07 Feb 2025 21:39:50 GMT</pubDate></item></channel></rss>