How to plot and calculate ekf2_*_Delay?

PX4 Autopilot
1

Hello everyone,

I am currently using intel T265 tracking camera to provide external position estimate to the ekf2 via mavros. I have set EKF2_AID_MASK to 24 (vision_position_fusion & vision_yaw_fusion) and ekf2_ev_delay is set to default (175 ms). The flight works really well and I have no complaints regarding it. But i wonder if i could optimize it by actually finding out the difference between IMU timestamp and vision timestamp. I tried to use the FlightPlot to plot imu & vision timestamps but i couldn’t figure it out. Here (https://dev.px4.io/v1.10/en/ros/external_position_estimation.html) it shows that they have plotted vehicle_attitude_0.q[0] and vehicle_vision_attitude_0.q[0] to find the difference between IMU sensor timestamp and Vision sensor timestamp. My log files doesn’t show vehicle_vision_attitude_0.q[0] maybe because I am sending position and not velocity (Not sure about this). Can someone help me figure out how to calculate the EKF2_*_DELAY?

Thank you,
Rajas

1 Like
2

I recall seeing some question like this somewhere… Don’t want to say for sure but I think the topic names have changed in recent versions…

3

Did you forget to set this parameter? I am able to find vehicle_vision_attitude_0.q[0] in log file. I am using PX4 firmware v1.8.2.

To enable logging of EV rates set bit 7 (Computer Vision and Avoidance) of SDLOG_PROFILE.