# QVIO data and EKF2 integration.

Source: https://forum.modalai.com/topic/3291/qvio-data-and-ekf2-integration
Category: VOXL SDK and Software (https://forum.modalai.com/category/47/voxl-sdk-and-software)
Tags: ros
Posted: 2024-04-03 21:33:04 UTC by SAGAR SARKAR
Replies: 0 · Views: 511

## SAGAR SARKAR · 2024-04-03 21:33:04 UTC

I am trying to modify the VIO algorithm. I was going through the PX4 documentation: [Using Vision or Motion Capture Systems for Position Estimation](https://docs.px4.io/main/en/ros/external_position_estimation.html). They mentioned that in order to add the VIO data in the EKF2, it needs to be published either in "/mavros/vision_pose/pose" or "/mavros/odometry/out". I launched the voxl_mpa_to_ros and px4 launch files, here is the all available rostopics:

![01.png](https://forum.modalai.com/assets/uploads/files/1712180322734-01.png) ![02.png](https://forum.modalai.com/assets/uploads/files/1712180327812-02.png) ![03.png](https://forum.modalai.com/assets/uploads/files/1712180331720-03.png) 

I set the QGC parameters as follows:

![Screenshot from 2024-04-03 17-00-48.png](https://forum.modalai.com/assets/uploads/files/1712179956733-screenshot-from-2024-04-03-17-00-48.png) ![Screenshot from 2024-04-03 17-00-32.png](https://forum.modalai.com/assets/uploads/files/1712179956800-screenshot-from-2024-04-03-17-00-32.png) ![Screenshot from 2024-04-03 17-00-16.png](https://forum.modalai.com/assets/uploads/files/1712179956867-screenshot-from-2024-04-03-17-00-16.png) 

But there is nothing that's being published in both those topic. So I am wondering how is the VIO data being send to PX4 to get it fused with EKF2. I can see the ODOMETERY data through the MAVLink Inspector, but through mavros. I tried moving the UAV manually in the lab and plotted the position data from the "/qvio/pose" and "/mavros/local_position/pose". Here are the plots:

![Qvio and Local pose.png](https://forum.modalai.com/assets/uploads/files/1712179585793-qvio-and-local-pose.png) ![Qvio and local height.png](https://forum.modalai.com/assets/uploads/files/1712179585881-qvio-and-local-height.png) 

As per the mavros documentation "/mavros/local_position/pose" published fused pose which means the PX4 infact fusing the VIO pose estimates. So, can anyone explain how?