@Muqing-Cao You can get the VIO data from the ROS1 and ROS2 Topic /ov_overlay , /ov, or /qvio depending on which VIO you are using. Both have the same type interfaces available so either should work. Yes, you will be able to get run the commands on a host computer and as long as they are on the same ROS_DOMAIN_ID, for ROS2 this should be automatic.

Hello all, I was doing a bit of testing with voxl-open-vins-server and noticed an issue where the PX4 flight mode remains in position mode when the quality dropped below the the EKF2_EV_QMIN. I am seeing that QGC is sending a message saying that the system is falling back into altitude mode, but the flight mode never changes. I changed the PX4 parameter for EKF2_EV_QMIN to 90, however it seems to stay in position mode even though when I look at the PX4 logs the VIO quality drops below the QMIN value. I tested qvio to see if this was a voxl-px4 issue, but voxl-qvio-server switches into altitude mode when the quality drops below the the QMIN value. My question is why is it that when Open-vins reports that the quality is less than the QMIN it stays in position mode?

Thank you for your time,
Aaron Porter

@george-kollamkulam

Based on what you gave here. Yes, if voxl-camera-server is not running then there is nothing going into the ros2 topics to be published by voxl-mpa-to-ros2. The main way to figure out why voxl-camera-server is not running is to run voxl-camera-server on the VOXL2's command line. If need be you can also use the debug flags not sure what they are off the top of my head but you can find them by using voxl-camera-server -h.

First lets find out why voxl-camera-server is not working then we will have a better idea if mpa-to-ros2 has a problem.

The overall goal is just to get time synced between the Lidar and the VOXL2's IMU. Oddly enough, I was looking through the voxl-kernel for qrb5165 and the driver for PTP is there. Is the physical layer chip not able to support PTP?

Where I see the driver in the Kernel:
https://gitlab.com/voxl-public/system-image-build/qrb5165-kernel/-/tree/qrb5165-ubun1.0-14.1a/drivers/ptp?ref_type=heads

So we are trying to sync the time between the VOXL2 and an external lidar that are connected via ethernet. We can collect the data from the Lidar however due to the timestamps between the Lidar's real time clock and the VOXL2's monotonic time stamp there is Skewing occurring because the Lidar does not have a IMU to use. The question here is how would someone solve this issue?

PTP was attempted of but the problem is that the VOXL2's Linux Kernel does not support software-transmit when inspected using ethtool. If there is a way to get around this that would be ideal. Then it would just be working with getting the Monotonic clock to work with the Real Time Clock.

The thought of collecting the time of the lidar and then setting an offset to match up with with the monotonic clock was purposed but due to the query-response nature of the setup. There is an unknown round trip delay from the VOXL2 query to the the Lidar's response back to the VOXL2.

Also alternative suggestions are welcomed if there is a far simple way then sure, but the request is to avoid adding additional hardware.

Thank you for your time,
Aaron Porter

So for anyone that has the same a question about VFC as I did, this post is just to answer the question.

The purpose is to be a more robust system that doesn't get PX4's state and EKF from being corrupted when VIO fails. So in essence it is a more graceful way for the drone to fail out of Position mode into altitude mode. So the functionality and performance seem to be the same as the drone using position odometry data just in offboard mode. More changes maybe in the wood works but as of June, 2025, this is its purpose so far.

@Judoor-0, are you using the ModalAI TOF? Depending on the point cloud format, I see that there is a way to get the confidence level and the rgb values from the point cloud data. You might be able to use the RGB as intensity and the confidence value for Noise information. I can test it out if you are using a ModalAI TOF to check the PointCloud formatting just so I can give you a full answer.

So something that I was seeing while testing this was having a bit of instability with Open VINS flying and altitude flying (Not Using VFC). I was seeing that voxl-open-vins-server stated that the IMU temperature was too high and kept resetting. After letting the VOXL2 cool down for a day I was able to have the Drone Fly in VFC mode but not sure how it flew compared to Position mode using VIO.

@Muqing-Cao You can get the VIO data from the ROS1 and ROS2 Topic /ov_overlay , /ov, or /qvio depending on which VIO you are using. Both have the same type interfaces available so either should work. Yes, you will be able to get run the commands on a host computer and as long as they are on the same ROS_DOMAIN_ID, for ROS2 this should be automatic.

Thank you, I was playing around with it.
Seems like for the controller it is a bit difficult since all main the buttons on the Xbox controller are mapped to the same channels. But at least then are set to different values.

Hello,

I am playing around with VFC on one of the Starlings 1. I am able to takeoff in altitude mode and change over to Offboard mode. I thought that changing to offboard mode from altitude would cause the drone to go into VFC_Altitude mode however, I get a message in QGC that the mode is VFC_Manual and feels similar to manual mode as well. Not sure if I am missing something? Am I wrong in thinking that it should be in VFC_Altitude?

I am using a joystick controller instead of an RC controller.

Thank you for your time,
Aaron Porter

Question about the frame rate on the voxl cameras. Is there a way to get voxl-camera-server to lock the frame rate regardless of the Exposure? We noticed that auto exposure will cause the camera frame rate to lower on cameras that are in darker locations compared to the cameras that are located in brighter areas. Just asking if there is a way to make it so that we can have a consistent frame rate regardless of where the camera is looking and the lighting in those areas?

Thank you,
Aaron Porter