HI @anbello, I am getting x,y,z , i can also get the quaternion from the pozyx system(ENU). The pozyx tag communicate with 4 others anchors and give me x,y,z coordinates
then i send then i publish them with PoseStamped trough the /mavros/mocap/pose. i dd not change nothing since ROS is supposed to convert data to NED . i will read the tips you gave me and let you know
Please show the ATT_POS_MOCAP message you receive from GCS , if you are using Mission Planner do CTRL-F and select Mavlink Inspector.
From you example above it seems you do not send the quaternions , please make sure that you map the pose topic correctly as described here:
https://dev.px4.io/master/en/ros/external_position_estimation.html#relaying_pose_data_to_px4
@chobitsfan could give you some guidance on this.
that is what i am getting
Do i have to use VISION_POSE_ESTIMATE
I think one of my big problem is with the frame coordinates system .
I manage to get quaternion from the pozyx tag . i get qx=0,5 qy=0,5 qz=0,5 qw=0,5
I dont see the vision signal , like I wrote before,
ArduPilot can process both Quaternions and Euler Angles, but just make sure that Mavros read Pozyx and output the correct signal to MavLink.
I am working with EKF2, and on the link you send me :
https://dev.px4.io/master/en/ros/external_position_estimation.html#relaying_pose_data_to_px4
Only vision pipeline is allowed
that means i have to remap the pose topic i get from the pozyx to the /mavros/vision/pose?
because i was sending pose to /mavros/mocap/pose
I suspect the wiki is outdated, just to make sure you can ask @vooon for confirmation/guidance on the Mavros Channel
Now i understand the Frame Transformation issues . But i still have some questions
I can get the position as well as the quaternion from the pozyx’s tag
my issues is about how to get the name of the origin of the world frame of the pozyx , and the name of the frame of the pozyx’s tag , because while i am sending mocap_data i also set header.frame_id=“pozyx”,
should i use it to send the transformation frame ?
Another question is that should i send the mocap/pose and send the transform to the /tf or only send the frame transformation ?
Hi Monsieur ppoirier . I read a lot about the transformation data and i found that i do not need to transform my data since i am able to get the position as well as the quaternion(transalation and rotation according to my world origin). I still face the same issues about my x, and y coordinates . Can i try to send the data i receive to mavros/vision_pose/pose ?
Hello Joel
If you you use quaternions, You could work with mocap pose messages because vision is using Euler angles
Hi you are right , but in the px4 tutorial
If you’re working with EKF2, only the “vision” pipelines are supported. To use MoCap data with EKF2 you will have to remap the pose topic that you get from MoCap:
- MoCap ROS topics of type
geometry_msgs/PoseStampedorgeometry_msgs/PoseWithCovarianceStampedmust be remapped to/mavros/vision_pose/pose. Thegeometry_msgs/PoseStampedtopic is most common as MoCap doesn’t usually have associated covariances to the data. - If you get data through a
nav_msgs/OdometryROS message then you will need to remap it to/mavros/odometry/odom.
that is what is said about the mocap pipeline. I don’t know ob it is also relevant for Ardupilot ?
hi , it is also possible to use quaternion with vision message since it is needed to use PoseStamped object . I tried it but i got the same undesired result .
I have another question Monsieur ppoirier . since the north position get by the autopilot is not static ,
When i get the north direction with 0 degree after some time , i have to adjust the drone again to head to the north . I also tried to align my positioning system with the x axis heading the north direction . but i dint have any instrument to have an accurate direction .
In the case that the pozyx system and the x axis of the drone are not perfectly aligned to the north direction , is that still possible to perform external navigation data with a certain accuracy ?
thanks
If you experience problems related to compass, if you build from master you can disable compass, otherwise I cannot really help because I don’t use Pozyx.
@chobitsfan might