The merge is so slow

[940222JESUS]

Hi Now I'm working with it but I have a issue, when I use it the result of the merge is so slow, the time delay is three or more seconds, it's normal? I'm using Ros Melodic and Gazebo for simulate the scanners, but when in the simulation I put an object the topic of the one of the scanners show the object immediately (in rviz) but the topic of the merge show the object later than three or more seconds, it work with this times or I have to change something?

Thanks

[trigal]

I've never heard of this kind of issues, and we're used to use the merger in our vehicle in "real-time" (as far as realtime can be in ROS). Have you changed something in the code? Maybe is something that has to do with the queues and timestamps, I don't really know, but I can say that it's not normal.

[pietrocolombo]

Is the frequency of the lasers you merge the same?

[940222JESUS]

Is the frequency of the lasers you merge the same?

You mean to the script of the scanners in Gazebo or the script of ira laser?

This is the launch file of ira laser

This is the script of scanners (Gazebo plugin)

In this image only can see one of the scanners but the configuration is the same in the two scanners

[940222JESUS]

I've never heard of this kind of issues, and we're used to use the merger in our vehicle in "real-time" (as far as realtime can be in ROS). Have you changed something in the code? Maybe is something that has to do with the queues and timestamps, I don't really know, but I can say that it's not normal.

Ok, thank you. Then I suppose that there are something wrong.

[940222JESUS]

https://youtu.be/LalHqYyB2ic

In this video show the issue

[trigal]

no idea on this side.. maybe the TF tree is updated with delay on your configuration; check the timestamps of the laser messages and the TF messages too; @pietrocolombo was talking about the frequency of the simulated lidar, I think both are at 5Hz right? and please, please, please, paste text/code next time, not screenshots ;-)

[940222JESUS]

no idea on this side.. maybe the TF tree is updated with delay on your configuration; check the timestamps of the laser messages and the TF messages too; @pietrocolombo was talking about the frequency of the simulated lidar, I think both are at 5Hz right? and please, please, please, paste text/code next time, not screenshots ;-)

ok, this is the code

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0 0 0 0 0 0 $(arg laser_visual) 5 270 1 2.35619 6.89405 0.070 16.0 0.015 gaussian 0.0 0.01 scan_izq base_scan_1

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` And yes, both scanners are update at 5hz. And for my TF three i use the robot_state_publisher, this is the launch and the frecuency is 50 hz ` `

[940222JESUS]

no idea on this side.. maybe the TF tree is updated with delay on your configuration; check the timestamps of the laser messages and the TF messages too; @pietrocolombo was talking about the frequency of the simulated lidar, I think both are at 5Hz right? and please, please, please, paste text/code next time, not screenshots ;-)

ok, this is the code

<gazebo reference="base_scan_1"><!--base_scan_1--> <sensor type="ray" name="lds_lfcd_sensor_1"><!--name="lds_lfcd_sensor"--> <pose>0 0 0 0 0 0</pose><!--0 0 0 0 0 0--> <visualize>$(arg laser_visual)</visualize> <update_rate>5</update_rate><!--5--> <ray> <scan> <horizontal> <samples>270</samples><!--360 270--> <resolution>1</resolution> <min_angle>2.35619</min_angle><!--0.0 2.35619--> <max_angle>6.89405</max_angle><!--6.28319 6.89405--> </horizontal> </scan> <range> <min>0.070</min><!--0.120--> <max>16.0</max><!--3.5--> <resolution>0.015</resolution> </range> <noise> <type>gaussian</type> <mean>0.0</mean> <stddev>0.01</stddev> </noise> </ray> <plugin name="gazebo_ros_lds_lfcd_controller_1" filename="libgazebo_ros_laser.so"><!--name="gazebo_ros_lds_lfcd_controller"--> <topicName>scan_izq</topicName> <!--scan_izq--> <frameName>base_scan_1</frameName><!--base_scan_1--> </plugin> </sensor> </gazebo>

<launch> <node pkg="ira_laser_tools" name="laserscan_multi_merger" type="laserscan_multi_merger" output="screen"> <param name="destination_frame" value="base_footprint"/> <param name="cloud_destination_topic" value="/merged_cloud"/> <param name="scan_destination_topic" value="/scan_multi"/> <param name="laserscan_topics" value ="/scan_der /scan_izq " /> <!-- /scan_atras LIST OF THE LASER SCAN TOPICS TO SUBSCRIBE --> <param name="angle_min" value="-3.141592"/> <param name="angle_max" value="3.141592"/> <param name="angle_increment" value="0.0058"/> <param name="scan_time" value="0.0333333"/><!--0.0333333--> <param name="range_min" value="0.30"/> <param name="range_max" value="25.0"/> </node> </launch>

And yes, both scanners are update at 5hz. And for my TF three i use the robot_state_publisher, this is the launch and the frecuency is 50 hz

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sorry but in the comment no appears the code, and i'm trying to put it but it doesn't appear. But the update is 50 hz

[940222JESUS]

sorry i unintentionally press the button that close this issue.

[trigal]

what is your system configuration? can you upload a picture of your TF tree? and please check the timestamps of the laser messages.

[940222JESUS]

what is your system configuration? can you upload a picture of your TF tree? and please check the timestamps of the laser messages.

What do you mean with system configuration?

This is the TF tree

This is the rate of topic of the merge

This is the rate of topic of the one scan, the frequency is 8hz