Ouster lidar os1 64

[islamtalha01]

Can this package be used for calibration of ouster os2 64 and Ip camera with this package? if it is possible then kindly guide me to complete the procedure I am doing as the research intern at NUST Pakistan. Kindly help me to achieve this task.

[chinitaberrio]

Just checkin the ROS driver for the Ouster lidar, I think it should work as it has the ring field in the point time, which is a requirement for the usage of the package.

[islamtalha01]

I am trying but if there is an issue I will let you know. kindly help me in this regard.

On Fri, Sep 3, 2021 at 7:34 AM Stephany Berrio @.***> wrote:

Just checkin the ROS driver for the Ouster lidar https://github.com/ouster-lidar/ouster_example/blob/master/ouster_ros/include/ouster_ros/point.h, I think it should work as it has the ring field in the point time, which is a requirement for the usage of the package.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-912207254, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27F3ZIMIBCDEVEQHVL3UAAX4NANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[islamtalha01]

I am trying with ouster os1 64 and USB camera. both lidar and USB camera drivers are installed and they are also running pretty well individually. I think I am mistaking in configuring my config file. I am attaching the screenshot of the config file and please tell me where I am mistaking. I also attached the warning I am getting and also my viz is not showing the output of the camera and lidar when running the lidar_camera calibration tool.

On Fri, Sep 3, 2021 at 10:50 AM MUHAMMAD TALHA @.***> wrote:

I am trying but if there is an issue I will let you know. kindly help me in this regard.

On Fri, Sep 3, 2021 at 7:34 AM Stephany Berrio @.***> wrote:

Just checkin the ROS driver for the Ouster lidar https://github.com/ouster-lidar/ouster_example/blob/master/ouster_ros/include/ouster_ros/point.h, I think it should work as it has the ring field in the point time, which is a requirement for the usage of the package.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-912207254, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27F3ZIMIBCDEVEQHVL3UAAX4NANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

I'm unable to see the attached files

[islamtalha01]

kindly check the pics in the folder uploaded on google drive. https://drive.google.com/drive/folders/1lQMeMv0lzVR_JxMgSZebeir5DbGxhlOL?usp=sharing

On Fri, Sep 3, 2021 at 11:23 AM Stephany Berrio @.***> wrote:

I'm unable to see the attached files

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-912289319, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27BF2Z7ECVL35UDGM3TUABSULANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

You need to change the global frame in rviz to your lidar frame

[islamtalha01]

There is no option to change the frame to ouster in that rviz window. I think my topics in the cfg file are not correct. How to find the exact topic of my sensor in ros. Kindly help me in this regard.

On Fri, 3 Sep 2021, 1:10 PM Stephany Berrio, @.***> wrote:

You need to change the global frame in rviz to your lidar frame

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-912347767, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27FZYY3RPZHGKOLBRXLUAB7GTANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

You should be able to change the global frame in rviz, refer to this document: http://wiki.ros.org/rviz/UserGuide Once you have launched all your drivers, open a new terminal and type rostopic list, you should be able to see all the topics published by the drivers, you can also take a look at these links: http://wiki.ros.org/rostopic http://wiki.ros.org/ROS/Tutorials/UnderstandingTopics

[islamtalha01]

Thanks, a lot Stephany. I will look into it and come back to you. I am very thankful to you for this help. I am newby that's why I am asking all these questions. again thanks a lot.

On Fri, Sep 3, 2021 at 2:49 PM Stephany Berrio @.***> wrote:

You should be able to change the global frame in rviz, refer to this document: http://wiki.ros.org/rviz/UserGuide Once you have launched all your drivers, open a new terminal and type rostopic list, you should be able to see all the topics published by the drivers, you can also take a look at these links: http://wiki.ros.org/rostopic http://wiki.ros.org/ROS/Tutorials/UnderstandingTopics

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-912411298, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27HZMDIACBE6NY6HB6DUACK3RANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[islamtalha01]

Hello Stephany, Is there any other way to communicate with you in this regard? Facebook, WhatsApp, or MS teams. I am asking this because there we can contact easily and often. I am a beginner, I just need your help for some time otherwise there is no support of ROS with ouster in this regard on the internet. kindly help me. I will not create inconvenience for you. Thank you.

On Sat, Sep 4, 2021 at 1:37 AM MUHAMMAD TALHA @.***> wrote:

I am able to get the camera and lidar stream in the rviz window. now when I trying to extract features from a live feed. it is not happening. I have recorded the video kindly see the video and help me in this regard. i will be very thankful to you for this. please see video in the link below.

https://drive.google.com/drive/folders/1lQMeMv0lzVR_JxMgSZebeir5DbGxhlOL?usp=sharing

On Fri, Sep 3, 2021 at 2:52 PM MUHAMMAD TALHA @.***> wrote:

Thanks, a lot Stephany. I will look into it and come back to you. I am very thankful to you for this help. I am newby that's why I am asking all these questions. again thanks a lot.

On Fri, Sep 3, 2021 at 2:49 PM Stephany Berrio @.***> wrote:

You should be able to change the global frame in rviz, refer to this document: http://wiki.ros.org/rviz/UserGuide Once you have launched all your drivers, open a new terminal and type rostopic list, you should be able to see all the topics published by the drivers, you can also take a look at these links: http://wiki.ros.org/rostopic http://wiki.ros.org/ROS/Tutorials/UnderstandingTopics

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-912411298, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27HZMDIACBE6NY6HB6DUACK3RANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

If you have any issues with your ouster driver please address them at: https://github.com/ouster-lidar/ouster_example, we can only support problems related to the camera-lidar calibration package.

[islamtalha01]

I have no issue regarding driver i am just saying that theyvhave no support regarding camera lidar calibration that's why I am asking about your package. Did you saw my video that i upload on the Google drive.

On Mon, 6 Sep 2021, 1:40 AM Stephany Berrio, @.***> wrote:

If you have any issues with your ouster driver please address them at: https://github.com/ouster-lidar/ouster_example, we can only support problems related to the camera-lidar calibration package.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-913224122, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27AJKIJBBQOYH3SYYM3UAPITXANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

Prepare a rectangular chessboard printout, preferably with odd-numbered grid dimensions (e.g. 9x7, 11x13) Firmly attach the chessboard on a rigid, opaque, and rectangular board such that both their centres align and their edges remain parallel to one another. Choose a suitable stand that can mount the target with little to no protruding elements from the board's edges. Mount the target on the stand such that it is tilted at an angle of 45-60 degrees with respect to the ground plane.

You also need to adjust the experimental region for your case. The in rqt_reconfigure, feature_extraction variables correspond to the bounds of the 3D experimental region along the LiDAR's x,y,z axis: x_min [rear], x_max [front] with range of [-6.0, 6.0] y_min [right], y_max [left] with range of [-5.0, 5.0] z_min [bottom], z_max [top] with range of [-2.0, 2.0]

[islamtalha01]

What does it mesns by adjust the experimental region? How we can do it? We have to edit some file?

On Mon, 6 Sep 2021, 1:53 AM Stephany Berrio, @.***> wrote:

Prepare a rectangular chessboard printout, preferably with odd-numbered grid dimensions (e.g. 9x7, 11x13) Firmly attach the chessboard on a rigid, opaque, and rectangular board such that both their centres align and their edges remain parallel to one another. Choose a suitable stand that can mount the target with little to no protruding elements from the board's edges. Mount the target on the stand such that it is tilted at an angle of 45-60 degrees with respect to the ground plane.

You also need to adjust the experimental region for your case. The in rqt_reconfigure, feature_extraction variables correspond to the bounds of the 3D experimental region along the LiDAR's x,y,z axis: x_min [rear], x_max [front] with range of [-6.0, 6.0] y_min [right], y_max [left] with range of [-5.0, 5.0] z_min [bottom], z_max [top] with range of [-2.0, 2.0]

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-913225825, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27AEFGXAKIRCHM2RPNTUAPKFBANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[darrenjkt]

When you run roslaunch cam_lidar_calibration run_optimiser.launch, two windows will pop up. One is Rviz, the other is the rqt_reconfigure window. The rqt_reconfigure window is where you can adjust the experimental region. That window basically sets the maximum and minimum x,y and z value such that you only allow certain points through within those bounds and filter the rest out.

[islamtalha01]

Okkay got it. But the thing is that when i am changing this values in my previous exp nothing happens. No change in region happens. What would be the reason? I recorded bag file containing img and point cloud but when i am running this file and adjusting my exp region nothing happens. There is a error of no tranform found or something like what is this issue?

On Mon, 6 Sep 2021, 7:38 AM Darren Tsai, @.***> wrote:

When you run roslaunch cam_lidar_calibration run_optimiser.launch, two windows will pop up. One is Rviz, the other is the rqt_reconfigure window. The rqt_reconfigure window is where you can adjust the experimental region. That window basically sets the maximum and minimum x,y and z value such that you only allow certain points through within those bounds and filter the rest out.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-913294920, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27GQCJ2YF5OCOCTRTLLUAQSRRANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

Make sure the topic name is correct. Also you can refer to this readme file: https://github.com/chinitaberrio/cam_lidar_calibration

[darrenjkt]

Before adjusting anything in the rqt_reconfigure, you should be able to see the entire pointcloud if you've configured RViz correctly

[islamtalha01]

Darren I am seeing both lidar point clouds and camera stream by playing my rec bag file. But it is showing some issues of transform. My bag file has no \tf topics. Darren can we talk in something that is much fluent or easy like Skype or ms teams. I am doing an intern at university, In a hour i will have the sensor os1 in my hand, can you help me with that?. On email it is difficult to mention things in robust manner. It will be the matter of 10 to 20 minutes. But by this way i will be sure in these minutes that this package is gonna work for or not. Kindly think about it and let me know, otherwise email will the option i opt for. Kindly do me favor of 10 to 20 minutes.

On Mon, 6 Sep 2021, 9:17 AM Darren Tsai, @.***> wrote:

Before adjusting anything in the rqt_reconfigure, you should be able to see the entire pointcloud if you've configured RViz correctly

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-913325891, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27BRS3MLJSTVTFBW2OLUAQ6HDANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[islamtalha01]

I am able to get the camera and lidar stream in the rviz window. now when I trying to extract features from a live feed. it is not happening. I have recorded the video kindly see the video and help me in this regard. i will be very thankful to you for this. please see video in the link below. https://drive.google.com/drive/folders/1lQMeMv0lzVR_JxMgSZebeir5DbGxhlOL?usp=sharing

On Fri, Sep 3, 2021 at 2:52 PM MUHAMMAD TALHA @.***> wrote:

Thanks, a lot Stephany. I will look into it and come back to you. I am very thankful to you for this help. I am newby that's why I am asking all these questions. again thanks a lot.

On Fri, Sep 3, 2021 at 2:49 PM Stephany Berrio @.***> wrote:

You should be able to change the global frame in rviz, refer to this document: http://wiki.ros.org/rviz/UserGuide Once you have launched all your drivers, open a new terminal and type rostopic list, you should be able to see all the topics published by the drivers, you can also take a look at these links: http://wiki.ros.org/rostopic http://wiki.ros.org/ROS/Tutorials/UnderstandingTopics

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-912411298, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27HZMDIACBE6NY6HB6DUACK3RANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

The first step is to have the proper setup:

Prepare a rectangular chessboard printout, preferably with odd-numbered grid dimensions (e.g. 9x7, 11x13) Firmly attach the chessboard on a rigid, opaque, and rectangular board such that both their centres align and their edges remain parallel to one another. Choose a suitable stand that can mount the target with little to no protruding elements from the board's edges. Mount the target on the stand such that it is tilted at an angle of 45-60 degrees with respect to the ground plane.

The tool provided won't work if you are holding the checkerboard as it needs to be isolated from the background by adjusting the experimental region like this:

[darrenjkt]

You can send me an email at jtsa5115@uni.sydney.edu.au and we can chat further.

[ygsq-123]

Is the problem of adjusting the rqt_reconfigure window but the point cloud range unchanged? I also encountered the same problem. Can you tell me how to solve it, thank you.

[islamtalha01]

I am still facing this problem so if there any solution will come to me I will tell you

On Wed, Sep 8, 2021 at 7:01 AM ygsq-123 @.***> wrote:

Is the problem of adjusting the rqt_reconfigure window but the point cloud range unchanged? I also encountered the same problem. Can you tell me how to solve it, thank you.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-914817501, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27BJA3BTBAO66ED7JUTUA27YXANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[chinitaberrio]

Can you show me the point cloud topics that appear on rviz? Eg.

Which rostopic are you displaying on rviz?

[darrenjkt]

I've made some annotations for the rviz setup process. Let me know if this helps.

[islamtalha01]

Thanks, I'll check it out.

On Wed, 8 Sep 2021, 2:27 PM Darren Tsai, @.***> wrote:

I've made some annotations for the rviz setup process. Let me know if this helps.

[image: RVIZ instructions] https://user-images.githubusercontent.com/39115809/132483784-09398b0c-0009-4c3f-80c2-9bf19b1e6aeb.png

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#issuecomment-915072173, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27BNASQRYKHYYUQ22FTUA4UBVANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[islamtalha01]

Hi, Darren, I have tried the things you said in the last reply but i am not able to extract the checkerboard. some errors appeared which I attached a screenshot. the second thing using recorded bag file How to apply feature extraction? do i have to pause the bag file at some point? or just use feature extraction when the rosbag file is playing?.

On Tue, Sep 21, 2021 at 6:18 AM Darren Tsai @.***> wrote:

Closed #4 https://github.com/acfr/cam_lidar_calibration/issues/4.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#event-5331986282, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27AX7YC2SVHEKH5ARYTUC7MPXANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[islamtalha01]

Now i am able to extract the checkerboard but i am getting an error due to which i am not able to calibrate. I have attached the error screenshot. Kindly reply as soon as possible.

On Thu, Sep 30, 2021 at 4:21 AM MUHAMMAD TALHA @.***> wrote:

Hi, Darren, I have tried the things you said in the last reply but i am not able to extract the checkerboard. some errors appeared which I attached a screenshot. the second thing using recorded bag file How to apply feature extraction? do i have to pause the bag file at some point? or just use feature extraction when the rosbag file is playing?.

On Tue, Sep 21, 2021 at 6:18 AM Darren Tsai @.***> wrote:

Closed #4 https://github.com/acfr/cam_lidar_calibration/issues/4.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/acfr/cam_lidar_calibration/issues/4#event-5331986282, or unsubscribe https://github.com/notifications/unsubscribe-auth/AT4S27AX7YC2SVHEKH5ARYTUC7MPXANCNFSM5DG7XTMQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

[jvnsg]

Hey @islamtalha01, I have some similar issues like you had configuring the calibration tool for the Ouster LIDAR. Is there a way I can contact you directly to help me out?

[jogyul00]

I'm using the os1 64ch lidar, too. but I'm not able to extract the chekerboard. How did you do?? Help me, please. Just like your situation before, I adjust the rqt_reconfigure window but the point cloud range unchanged.

[TunnaBaitha]

Hey @islamtalha01 , I am facing the problem in Ouster LIDAR and Camera calibration. can you help me solve the problem.....

[TunnaBaitha]

did anybody get the solution of this issue? if so please help me to calibrate OS2 64 channel Lidar and camera .....

[mumu-o]

did anybody get the solution of this issue? if so please help me to calibrate OS2 64 channel Lidar and camera ..... Hi @TunnaBaitha I got the same issue when using OS2 64 channel LiDAR, but I still didn't find a solution yet. Have you solved it?

[chinitaberrio]

@mumu-o, What specific problem are you experiencing?

[mumu-o]

@mumu-o, What specific problem are you experiencing?

Hi @chinitaberrio, Thank you for your reply. I currently use the Ouster 64 channel LiDAR with a simple web cam for the calibration. I have modified the topics as the devices I used. However, It seems like I cannot isolate the point cloud data on the chessboard using rqt_reconfigure_para, even though I changed the config setting from rqt panel, the visualization of point cloud data didn't change. Please see the figure below. From the rqt window, the topic that related to point cloud listed on the left is the "feature_extraction". However, from my visualization window, when I change the "Cheesboard" topic to "feature_extraction/cheesboard", there is no point cloud data shown on the right. Only when I select "ouster/point", it works. My understanding is the "feature_extraction" topic tried to convey point cloud data from the LiDAR topic ("ouster/point"), however, it didn't work from my site. So when I use rqt to change the region, the points cannot be isolated. I am not sure if my understanding is correct. What should I do to adjust the ROI of the point cloud data? Thank you

[chinitaberrio]

@mumu-o Here are a few things to check first: 1) Read the readme carefully, showing what needs to be adjusted step by step. Could you ensure you have changed all the topics and extra parameters in the config file? 2)The only topic you must change in rviz is the camera_image and the reference frame. 3)Are you publishing camera_image, camera_info, and point cloud in the same reference time? This package works if the topics are in sync. 4) Have you calibrated your camera? Are the parameters correct in the camera_info topic? (without the correct intrinsic parameters, the package won't work.)

[mumu-o]

Hi @chinitaberrio, Thank you for the reply. 1.1), yes, I have change the topics and modified the camera information based on the result of camera calibration. 2),yes, I have changed the frame to the ouster_lidar frame, and the camera_image topic to /usb_cam/image_raw 3), I think this is the reason. I recorded a bag file using both lidar and camera topics and the figure below shows the timestamp.

2. Yes, I have finished calibrated the camera and changed the parameters based on the camera calibration result. I think the intrinsic parameters should be correct. I think the timestamp synchronization should be the reason, but I am so confused about how to synchronize the timestamp of two devices. Could you please give me some help? Thank you

[chinitaberrio]

@mumu-o 1) I can't see the camera info topic in your rosbags. Intrinsic parameters are required for the Extrinsic calibration. 2) you can check if the topics are synchronized by looking at the header timestamp, not the rosbag time.

[mumu-o]

@chinitaberrio

1. the intrinsic parameters are as below. I have modified the default value with these intrinsic values.
2. I am confused about how to check the header timestamp. If it works if the fps of two devices don't match? Thank you

[chinitaberrio]

2) In rqt_bag, select the topic with a right-click and go to view -> raw. Use the arrows in the subsequent panel to navigate. Access the 'header' dropdown, followed by the 'stamp' dropdown to view the timestamp, presented in both seconds and nanoseconds. Perform this for every topic and compare the seconds across all the ROS topics. If the difference is in the magnitude of seconds you need to synchronise your hardware, e.g. for ouster, you can use PTP.

[mumu-o]

@chinitaberrio Thank you so much, I think this is the reason. The timestamps of my two devices are as follow. I will work on synchronizing the timestamp.

[mumu-o]

Hi there, I'd like to share my solution to a potential issue that Ouster LiDAR users might encounter, as I faced a similar problem. In my setup, I used a simple webcam and the Ouster LiDAR O2.

1. First, ensure you've launched the LiDAR, camera, and calibration topics.
2. Change the frame (in my case, it was "os_sensor"), and the image topic (usb_cam/image_raw in my case). Note that the point cloud should be shown at this time. However, I cannot see the point cloud data.
3. If you're still encountering problems, it may be caused by non-synchronized timestamps from different devices. In my setup, I observed timestamps as shown below:
4. To address timestamp synchronization issues, follow the guide PTP. When configuring the PTP grand master clock, ensure your Ethernet interface supports hardware or software only. If it's software-only, don't forget to change the "time_stamp" from "hardware" to "software". After completing the PTP setup, your timestamps should be synchronized, as shown below:
5. Restart the LiDAR, camera, and calibration topics, and the package should work correctly: Hope this should resolve your issue. Correct me if I am wrong.