Packet loss while logging at high frequencies
Posted: Wed Sep 05, 2018 7:51 am
Hi everyone,
I am a student and for my internship I am trying to estimate the pose of a Crazyflie using Visual Inertial Odometry as one of the methods. Right now I am trying to increase the logging frequency of the Crazyflie 2.0 from the default 100Hz to a frequency of 1kHz. The reason for increasing this frequency is that I want to have as much IMU data as possible to supply to a VIO algorithm running on a separate PC. The estimate pose will then be send to the Crazyflie and used in its internal estimator. The camera signal will be sent over another receiver and there are no plans to incorporated in the Crazyflie. I am using the Crazyflie ROS package of Whoenig to receive and process the packets. The data is send over a connection with a data rate of 2MBps using the Crazyradio PA.
As discussed in a previous discussion this is quite easy to achieve. However, the packet loss at a sample rate of 1 ms in my setup is around 60% (see the figure below which displays the factor of packet received over packets send). The packet loss at a sample rate of 2 ms is around 20%. That the packet loss increase while logging at higher frequencies is not surprising, but for my application these numbers are far from ideal. So my question is, is there a way to decrease the packet loss at a sample rate of 1 or 2 ms?
While testing the packet losses I also discovered that for sample rate of 4 ms and above the average packet loss in my setup is around 5%. However, at a sample rate of 3 ms the packet loss is less then 1%. Is there an explanation for this low number of packet loss at 3 ms? And why is this not observed while sampling slower (especially 6 and 9 ms since they are multiples of 3 ms)?
Feel free to comment on anything regarding this project.
Thank you,
Maarten
EDIT: I maybe should add that I'm only logging the IMU data, I have turned the logging of the temperature, barometer, etc. off.
I am a student and for my internship I am trying to estimate the pose of a Crazyflie using Visual Inertial Odometry as one of the methods. Right now I am trying to increase the logging frequency of the Crazyflie 2.0 from the default 100Hz to a frequency of 1kHz. The reason for increasing this frequency is that I want to have as much IMU data as possible to supply to a VIO algorithm running on a separate PC. The estimate pose will then be send to the Crazyflie and used in its internal estimator. The camera signal will be sent over another receiver and there are no plans to incorporated in the Crazyflie. I am using the Crazyflie ROS package of Whoenig to receive and process the packets. The data is send over a connection with a data rate of 2MBps using the Crazyradio PA.
As discussed in a previous discussion this is quite easy to achieve. However, the packet loss at a sample rate of 1 ms in my setup is around 60% (see the figure below which displays the factor of packet received over packets send). The packet loss at a sample rate of 2 ms is around 20%. That the packet loss increase while logging at higher frequencies is not surprising, but for my application these numbers are far from ideal. So my question is, is there a way to decrease the packet loss at a sample rate of 1 or 2 ms?
While testing the packet losses I also discovered that for sample rate of 4 ms and above the average packet loss in my setup is around 5%. However, at a sample rate of 3 ms the packet loss is less then 1%. Is there an explanation for this low number of packet loss at 3 ms? And why is this not observed while sampling slower (especially 6 and 9 ms since they are multiples of 3 ms)?
Feel free to comment on anything regarding this project.
Thank you,
Maarten
EDIT: I maybe should add that I'm only logging the IMU data, I have turned the logging of the temperature, barometer, etc. off.