Hello to every one.

I am struggling with something related to the Visual Inertial Odometry of my voxl2 board and mavros. I am not able to understand if it is working correctly or not. Basically this is the behavior I am not understanding correctly.

I am using the tracking camera to estimate the position and the orientation of my uav. The resulting pose seems correct and the quality is good as well. I start also mavros, since I want to integrate my application with the ROS framework.

I am comparing the value present in the /qvio/pose topic and the one in the /mavros/local_position/pose that should be the estimated position from the uav point of view.

Results:

• Orientation: I am mainly considering the YAW. The Yaw tracks the IMU data directly, without taking into account the value generated from the /qvio/pose. There is an offset due to the initial rotation of the uav, and the rotation is inverted by sign

• Position: there is an offset. No very huge but the position seems to be filter with other things

I was wondering if these things are correct, and why

Regards.

Dear @Moderator, again many thanks for the reply. More or less it is clear to me the code structure. However, I am struggling with a something that I am not able to understand.

I am connected with QGround to the voxl2 board running px4 v 1.14. I went to the mavlink inspect pane to listen to the LOCAL_POSITION_NED. Even if I stop or disable the voxl-qvio-server, the position is still received from the autopilot. How is this possible? Who is sending this data?

@Moderator Thanks for the quick reply. Do you think that, inspecting that source code and studying the High level architecture, I am also able to completely substitute the vision hub input, to feed the autopilot with a slam-generated odometry?

Hi to all,

I am trying to add different sensors to improve the estimation of the local position (i.e. the Local_position_ned). However, everything I made to set the ekf2 (using the px4 variables ekf2_ev params and similar) is ignored by the autopilot. I am also interested to understand more how the vision hub shares information with the px4 control stack. Is there any reference?

Regards,

Hello,

I am using my voxl2 with vision hub module. I am able to fly in position and offboard sending control input via MAVROS.
However, now I am trying to send a custom localization to the voxl2 using MAVROS. In classical px4 architectures, after set up the ekf2 parameters (https://docs.px4.io/v1.12/en/ros/external_position_estimation.html) I just publish on the /mavros/vision_pose/pose topic to have the new position updated. However now seems that this position is ignored and I have the following doubts:

1 - The ekf2_ev parameters is correctly set and on local_position_ned the position received is the one of the vio module. Who publishes that information, since the /mavros/vision_pose/pose topic is empty?

2 - Is there a way to listen directly to the /mavros/vision_pose/pose topic?

Thanks,
Jonathan

@tom Thanks for the reply. I thought the same at the start. I also tried connecting with the ethernet cable, and the results were the same. Do you mind if any other issues can cause the same behaviour?

Hello guys,

I just reinstalled from scratch the SDK and the operating system of my voxl2 (from flashing the firmware to SDK 1.2). I can access the voxl2 portal, seeing cameras and similar. However, when I try to configure my UAV using QGroundControl, it is very slow to download the parameter list (20% of package loss rate). However, when it finished I had the error: Unable to retrieve the full set of parameters.

Sadly, in this state, I cannot access the configuration options of Qground (ie. RC configuration, flight mode and similar).
Where I am wrong? Before reinstalling everything, Qground was working!

Thanks,

Hi to all,

I am addressing a strange problem operating my voxl2 system with Visual Inertial Odometry. In particular, the system is very slow in responding to the vision input and suddenly rejects the position control.
In my architecture, I used qvio and px4 to communicate with the mavlink server. To get info from the autopilot I use both MAVROS and QgroundControl. In both cases, the output of the local position NED is very slow, preventing the system from being controlled in position.

For example, when I launch the MAVROS server along the qvio, asking for the local pose publication rate I have the following time:

rostopic hz /mavros/local_position/pose
subscribed to [/mavros/local_position/pose]
no new messages
no new messages
average rate: 2398.527
	min: 0.000s max: 0.009s std dev: 0.00097s window: 81
no new messages
no new messages
no new messages
average rate: 51.832
	min: 0.000s max: 3.038s std dev: 0.23866s window: 162
no new messages
no new messages
average rate: 38.837

This behaviour is also clear from the mavlink inspector from QgroundControl. Finally, I have another lag strange behaviour. The RC sticks are read with a very huge lag. For instance, the change in the control mode takes 4-5 seconds to be effective (also if I want to change from altitude to stabilized).

Have you some hint on how to solve this problem?