Laser scanner update rate on fuerte (completely broken) and groovy (incorrect) and drcsim (incorrect)
For comparing fuerte and groovy I'm looking at the scenario described here. The vehicle used there is equipped with a LIDAR that is supposed to produce scans with a update rate of 40Hz. It also has a camera that runs on a 10Hz update rate. The LIDAR update rate in fuerte, groovy and drcsim do not seem to be correct, being worst in fuerte and sort of "ok" in groovy and drcsim.
There are bug reports concerning this already: Bitbucket gazebo ticket #22, Thread on ROS Answers
/edit: More test data using "rosbag info --freq" on Bitbucket
What are the plans regardings this? Will the fuerte bug be fixed at some point or should we try switching to groovy right away? Also, does "rostopic hz" correctly consider sim time, or can this also be a source of confusion?
Measurements:
Directly after spawning the vehicle I get the following in groovy (with a 1.00 realtime factor):
kohlbrecher@opstation:~$ rostopic hz scan
subscribed to [/scan]
average rate: 29.364
min: 0.024s max: 0.052s std dev: 0.01059s window: 19
average rate: 32.283
min: 0.021s max: 0.052s std dev: 0.00869s window: 43
average rate: 32.508
min: 0.021s max: 0.052s std dev: 0.00869s window: 64
average rate: 32.617
min: 0.021s max: 0.052s std dev: 0.00856s window: 86
average rate: 32.646
min: 0.021s max: 0.052s std dev: 0.00840s window: 107
average rate: 32.829
min: 0.021s max: 0.052s std dev: 0.00815s window: 129
After also subscribing to an image I get (also 1.00 realtime factor):
kohlbrecher@opstation:~$ rostopic hz scan
subscribed to [/scan]
average rate: 32.864
min: 0.022s max: 0.050s std dev: 0.00804s window: 22
average rate: 32.114
min: 0.022s max: 0.050s std dev: 0.00835s window: 44
average rate: 31.857
min: 0.022s max: 0.058s std dev: 0.00915s window: 65
average rate: 31.332
min: 0.022s max: 0.058s std dev: 0.00944s window: 85
average rate: 31.538
min: 0.022s max: 0.058s std dev: 0.00896s window: 107
average rate: 31.844
min: 0.022s max: 0.058s std dev: 0.00853s window: 130
After additionally subscribing to point cloud data (0.76 realtime factor):
kohlbrecher@opstation:~$ rostopic hz scan
subscribed to [/scan]
average rate: 25.111
min: 0.022s max: 0.074s std dev: 0.01444s window: 18
average rate: 26.163
min: 0.022s max: 0.074s std dev: 0.01451s window: 37
average rate: 27.496
min: 0.022s max: 0.074s std dev: 0.01385s window: 58
average rate: 27.126
min: 0.022s max: 0.074s std dev: 0.01385s window: 75
average rate: 27.043
min: 0.022s max: 0.076s std dev: 0.01455s window: 95
The same done on fuerte:
Just after robot spawn (~4.6 realtime factor, reduces to ~1.3 on subscribing to scan ):
kohlbrecher@opstation ...