# x&y values zero in odometry

Source: https://forum.modalai.com/topic/1064/x-y-values-zero-in-odometry
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2022-06-29 15:44:50 UTC by howard
Replies: 8 · Views: 2095

## howard · 2022-06-29 15:44:50 UTC

Hi,
I am trying use VIO to fly my drone outdoors without gps, I am using voxl cam and have connected Pixhawk cube externally. I have followed all the steps, but in Mavlink inspector I am getting x&y odometry values as zero ,whereas it shows z value.What am I missing out? Can someone help please.

## Reply by Adrian Hidalgo (ModalAI staff) · 2022-06-29 16:20:31 UTC

Seems like VIO hasn't started up, that's why x & y are zeroed out. 

Try:
```
voxl-reset-qvio
```
Check to see if x & y have returned if not 

Another method to try is this:
```
systemctl restart voxl-qvio-server
```

## Reply by Adrian Hidalgo (ModalAI staff) · 2022-06-29 16:30:13 UTC

For a more in-depth explanation on qvio check our [docs](https://docs.modalai.com/voxl-qvio-server/)

## Reply by Cliff Wong (ModalAI staff) · 2022-06-29 16:37:09 UTC

Also after resetting vio-server, you can run voxl-inspect-qvio to monitor valid localization information. If that is good, it's very likely (since you're getting z telemetry) you need to activate external vision solution in px4:
https://docs.modalai.com/flying-with-vio/

Look at the **ekf2_aid_mask** and substitute any flight core reference for the cube. Likely your aid mask is 1, which is gps and px4 will not report odometry mav data (z is fusing baro+vision and why you get z and no xy).

## Reply by howard · 2022-06-29 18:45:07 UTC (in reply to Cliff Wong)

@Cliff-Wong Hey, thank you for the reply,will try the above mentioned, but when I try voxl-inspect-qvio I get correct output,even voxl-inspect-services shows that all the required seevices are running.Could there be any other problem?
Thank you

## Reply by Cliff Wong (ModalAI staff) · 2022-06-29 19:41:45 UTC

Good to hear voxl services are ok, that leads to PX4's ekf2_aid_mask. It should be 280, aka all the external vision inputs are on. Then you should see xy odom in QGC's mavlink inspector.

## Reply by howard · 2022-06-30 07:57:12 UTC

hey!
I just used version 1.12.3 of PX4-autopilot stable release and everything is working fine now.
I hope there are no bugs related to VIO in this version.
Thank you

## Reply by DarkKnightCH · 2022-07-01 15:25:14 UTC (in reply to Adrian Hidalgo)

@Adrian-Hidalgo Hi, do you know why when VIO hasn't started up, then x&y are zeroed out but z still has values?

Recently I am trying to use the Motion Capture(Mocap) to provide pose information to EKF2 instead of VIO pose. Therefore, I run the vrpn_client_ros and mavros to get the Mocap data and meanwhile I disabled the VIO by setting "en_vio=false". Then the EKF2 will diverge and after about 50 seconds, x & y are zeroed out but z still has values. 

https://forum.modalai.com/topic/919/using-motion-capture-systems-optitrack-for-position-estimation?_=1656684369036

## Reply by Adrian Hidalgo (ModalAI staff) · 2022-07-05 19:58:18 UTC

@DarkKnightCH I believe Cliff answered that but in case it was missed: "z is fusing baro+vision and why you get z and no xy"