# Lidar\_node process has died **URL:** \ **Category:** Ask\ **Created:** [June 26, 2023, 11:57am UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760 "2023-06-26T11:57:51Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![roboor](https://avatars.discourse-cdn.com/v4/letter/r/3bc359/32.png) [@roboor](https://forum.hello-robot.com/u/roboor)\ **Post date:** [June 26, 2023, 11:57am UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/1 "2023-06-26T11:57:51Z")
Hi everyone, Once I quit and restart navigation with a previously created map, in both cases of Funmap and stretch\_navigation, the launch is not successful. The terminal outputs the following error messages (stretch\_navigation): > _[ERROR] [1687772255.077072615]: Error, operation time out. RESULT\_OPERATION\_TIMEOUT! \* > [lidar\_node-7] process has died [pid 10882, exit code 255, cmd /opt/ros/noetic/lib/rplidar\_ros/rplidarNode \_\_name:=lidar\_node \_\_log:=/home/hello-robot/.ros/log/11ce94c8-1405-11ee-aef5-2d69b595ef22/lidar\_node-7.log]. > log file: /home/hello-robot/.ros/log/11ce94c8-1405-11ee-aef5-2d69b595ef22/lidar\_node-7.log_ > > _[WARN] [1687772256.213964382]: Timed out waiting for transform from base\_link to map to become available before running costmap, tf error: canTransform: target\_frame map does not exist… canTransform returned after 0.101011 timeout was 0.1._ The error message for launching Funmap is similar. To solve this I have tried `stretch_rp_lidar_jog.py --reset` without success. Currently the only way to solve this is a trivial reboot, so I am wondering why this is happening and how I can fix it. I am working on a Stretch RE2 in ROS 1 and everything is up to date. Thanks in advance, Noor ---
**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\ **Post date:** [June 27, 2023, 9:08pm UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/2 "2023-06-27T21:08:50Z")
Hi @roboor, based on the `[lidar_node-7] process has died` error, it looks like the lidar isn’t streaming data in ROS. Would you run the following four commands to verify that the lidar is able to stream data via the Python API? ```auto $ stretch_rp_lidar_jog.py --reset For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Reseting the sensor None [INFO] [rplidar]: Stoping motor $ stretch_rp_lidar_jog.py --motor_on For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Starting motor $ stretch_rp_lidar_jog.py --health For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Asking for health ('Good', 0) [INFO] [rplidar]: Stoping motor $ stretch_rp_lidar_jog.py --range For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Starting motor [INFO] [rplidar]: Asking for health [INFO] [rplidar]: starting scan process in normal mode 0: Got 76 measurments Scan [(11, 157.671875, 1114.5), (15, 162.125, 1103.25), (15, 170.171875, 231.5), (15, 167.53125, 1511.25), (15, 168.953125, 1514.0), (15, 184.984375, 1553.75), (15, 186.453125, 1574.0), (15, 187.875, 1584.5), (15, 193.015625, 847.0), (15, 202.515625, 621.5), (15, 209.8125, 607.0), (15, 211.328125, 619.75), (15, 212.6875, 634.75), (15, 215.515625, 667.25), (15, 216.953125, 662.25), (15, 218.46875, 646.25), (15, 219.9375, 631.0), (15, 221.484375, 617.25), (15, 223.015625, 604.25), (15, 224.46875, 591.75), (15, 234.359375, 147.5), (15, 234.78125, 145.0), (15, 236.234375, 142.5), (15, 237.6875, 140.0), (15, 239.15625, 138.0), (15, 255.859375, 472.75), (15, 257.4375, 470.75), (15, 259.015625, 470.0), (15, 260.359375, 469.25), (15, 261.875, 469.0), (15, 263.296875, 469.25), (15, 264.765625, 469.5), (15, 266.109375, 470.0), (15, 267.6875, 470.75), (15, 269.25, 472.25), (15, 270.453125, 473.75), (15, 271.9375, 475.5), (15, 273.359375, 478.0), (15, 275.0, 480.5), (15, 276.515625, 483.25), (15, 277.765625, 486.75), (15, 279.3125, 490.5), (15, 280.59375, 494.25), (15, 282.203125, 499.0), (15, 283.34375, 503.5), (15, 285.0, 508.25), (15, 286.28125, 513.75), (15, 287.859375, 519.5), (15, 289.21875, 526.25), (15, 290.765625, 532.75), (15, 291.921875, 540.0), (15, 293.515625, 548.25), (15, 295.0, 556.25), (15, 296.25, 566.0), (15, 297.71875, 576.0), (15, 299.140625, 586.0), (15, 300.484375, 597.0), (15, 302.046875, 609.5), (15, 303.328125, 622.25), (15, 304.875, 622.0), (15, 306.359375, 623.25), (15, 307.765625, 630.75), (15, 310.984375, 575.5), (15, 313.921875, 547.25), (15, 315.609375, 539.25), (15, 316.890625, 543.0), (15, 319.484375, 575.75), (15, 322.734375, 526.0), (15, 324.1875, 525.25), (15, 328.140625, 669.0), (15, 329.453125, 683.75), (15, 336.3125, 882.5), (15, 344.671875, 1223.75), (15, 346.125, 1219.0), (15, 347.53125, 1217.75), (15, 348.984375, 1218.0)] [INFO] [rplidar]: Stoping motor ``` If you don’t see any measurements, let’s collect a dmesg log using `REx_dmesg_monitor.py`. Run this CLI is a separate terminal before running the experiment. When the Lidar fails, return to this terminal to save the log. ---
**Author:** ![roboor](https://avatars.discourse-cdn.com/v4/letter/r/3bc359/32.png) [@roboor](https://forum.hello-robot.com/u/roboor)\ **Post date:** [July 4, 2023, 12:33pm UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/3 "2023-07-04T12:33:22Z")
Hi @bshah, I ran these commands, and somehow could not encounter the described issues anymore. If the lidar is causing problems again, I will run the commands again, to find out more. However, these are the results from running these commands at the time when the lidar and the nav launching worked perfectly fine: ```auto $ stretch_rp_lidar_jog.py --reset For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Reseting the sensor None [INFO] [rplidar]: Stoping motor $ stretch_rp_lidar_jog.py --motor_on For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Starting motor $ stretch_rp_lidar_jog.py --health For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Asking for health ('Good', 0) [INFO] [rplidar]: Stoping motor $ stretch_rp_lidar_jog.py --range For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. --------------------------------------------------------------------- [INFO] [rplidar]: Starting motor [INFO] [rplidar]: Asking for health [INFO] [rplidar]: starting scan process in normal mode 0: Got 56 measurments Scan [(15, 72.625, 6441.75), (15, 73.96875, 6404.75), (15, 75.28125, 6347.5), (15, 76.609375, 6315.0), (15, 77.9375, 6290.0), (15, 79.25, 6254.5), (10, 84.390625, 11549.5), (15, 88.359375, 10740.5), (15, 89.671875, 10762.0), (15, 90.984375, 10820.5), (15, 92.3125, 10953.5), (14, 152.015625, 732.0), (9, 153.46875, 720.75), (15, 156.109375, 711.75), (15, 187.9375, 657.0), (15, 233.453125, 145.0), (15, 234.828125, 143.0), (15, 236.140625, 140.75), (15, 237.46875, 138.75), (15, 239.359375, 136.75), (15, 241.859375, 134.0), (15, 259.640625, 506.25), (15, 261.109375, 502.0), (15, 262.328125, 500.0), (15, 263.953125, 498.0), (15, 264.96875, 496.0), (15, 266.578125, 495.25), (15, 267.609375, 494.5), (15, 269.21875, 493.0), (15, 270.5625, 492.75), (15, 271.671875, 494.75), (15, 278.609375, 2076.0), (1, 279.921875, 2066.5), (15, 281.234375, 2030.0), (4, 282.546875, 2030.0), (15, 283.859375, 2034.25), (9, 287.8125, 2037.25), (15, 294.03125, 4264.75), (15, 299.9375, 1581.25), (15, 305.578125, 1167.5), (15, 306.875, 1161.5), (15, 308.203125, 1173.75), (15, 312.515625, 5007.5), (15, 316.515625, 4468.5), (15, 317.828125, 4414.25), (15, 321.90625, 3118.5), (15, 323.28125, 3074.75), (15, 324.625, 3012.0), (15, 325.921875, 2973.75), (15, 339.078125, 3481.0), (15, 341.890625, 2582.25), (15, 343.21875, 2566.5), (15, 344.515625, 2551.25), (15, 345.84375, 2538.0), (15, 347.21875, 2526.75), (15, 348.5625, 2505.5)] [INFO] [rplidar]: Stoping motor ``` ---
**Author:** ![roboor](https://avatars.discourse-cdn.com/v4/letter/r/3bc359/32.png) [@roboor](https://forum.hello-robot.com/u/roboor)\ **Post date:** [September 12, 2023, 9:32am UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/4 "2023-09-12T09:32:22Z")
So now after quite some while of working in ROS2, I switched to ROS1 and after some tests, I stumbled again over the same issue where the rplidar does not reset itself: > **Summary** > > ```auto > hello-robot@stretch-re2-2029:~$ stretch_rp_lidar_jog.py --reset > For use with S T R E T C H (R) RESEARCH EDITION from Hello Robot Inc. > --------------------------------------------------------------------- > > [INFO] [rplidar]: Reseting the sensor > None > [INFO] [rplidar]: Stoping motor > > hello-robot@stretch-re2-2029:~$ roslaunch stretch_navigation mapping.launch > ... logging to /home/hello-robot/.ros/log/0803bf94-4e53-11ee-ba9c-fd8d52a91004/roslaunch-stretch-re2-2029-24694.log > Checking log directory for disk usage. This may take a while. > Press Ctrl-C to interrupt > Done checking log file disk usage. Usage is <1GB. > > started roslaunch server http://stretch-re2-2029:34783/ > > SUMMARY > ======== > > PARAMETERS > * /aggregator_node/analyzers/hardware/analyzers/Arm/find_and_remove_prefix: ['stretch_driver:... > * /aggregator_node/analyzers/hardware/analyzers/Arm/path: Arm > * /aggregator_node/analyzers/hardware/analyzers/Arm/type: diagnostic_aggreg... > * /aggregator_node/analyzers/hardware/analyzers/Base/find_and_remove_prefix: ['stretch_driver:... > * /aggregator_node/analyzers/hardware/analyzers/Base/path: Base > * /aggregator_node/analyzers/hardware/analyzers/Base/type: diagnostic_aggreg... > * /aggregator_node/analyzers/hardware/analyzers/EndOfArm/find_and_remove_prefix: ['stretch_driver:... > * /aggregator_node/analyzers/hardware/analyzers/EndOfArm/path: EndOfArm > * /aggregator_node/analyzers/hardware/analyzers/EndOfArm/type: diagnostic_aggreg... > * /aggregator_node/analyzers/hardware/analyzers/Head/find_and_remove_prefix: ['stretch_driver:... > * /aggregator_node/analyzers/hardware/analyzers/Head/path: Head > * /aggregator_node/analyzers/hardware/analyzers/Head/type: diagnostic_aggreg... > * /aggregator_node/analyzers/hardware/analyzers/Lift/find_and_remove_prefix: ['stretch_driver:... > * /aggregator_node/analyzers/hardware/analyzers/Lift/path: Lift > * /aggregator_node/analyzers/hardware/analyzers/Lift/type: diagnostic_aggreg... > * /aggregator_node/analyzers/hardware/analyzers/Pimu/find_and_remove_prefix: ['stretch_driver:... > * /aggregator_node/analyzers/hardware/analyzers/Pimu/path: Pimu > * /aggregator_node/analyzers/hardware/analyzers/Pimu/type: diagnostic_aggreg... > * /aggregator_node/analyzers/hardware/analyzers/Wacc/find_and_remove_prefix: ['stretch_driver:... > * /aggregator_node/analyzers/hardware/analyzers/Wacc/path: Wacc > * /aggregator_node/analyzers/hardware/analyzers/Wacc/type: diagnostic_aggreg... > * /aggregator_node/analyzers/hardware/path: Hardware > * /aggregator_node/analyzers/hardware/type: diagnostic_aggreg... > * /aggregator_node/path: Stretch > * /aggregator_node/type: diagnostic_aggreg... > * /joint_state_publisher/rate: 15.0 > * /joint_state_publisher/source_list: ['/stretch/joint_... > * /laser_filter/scan_filter_chain: [{'name': 'shadow... > * /lidar_node/angle_compensate: True > * /lidar_node/frame_id: laser > * /lidar_node/inverted: False > * /lidar_node/scan_mode: Boost > * /lidar_node/serial_baudrate: 115200 > * /lidar_node/serial_port: /dev/hello-lrf > * /robot_description: * /robot_state_publisher/publish_frequency: 15.0 > * /rosdistro: noetic > * /rosversion: 1.16.0 > * /stretch_driver/broadcast_odom_tf: True > * /stretch_driver/controller_calibration_file: /home/hello-robot... > * /stretch_driver/mode: navigation > * /stretch_driver/rate: 15.0 > * /stretch_driver/timeout: 0.5 > * /teleop_twist_keyboard/speed: 0.04 > * /teleop_twist_keyboard/turn: 0.1 > > NODES > / > aggregator_node (diagnostic_aggregator/aggregator_node) > gmapping_record_map (gmapping/slam_gmapping) > joint_state_publisher (joint_state_publisher/joint_state_publisher) > laser_filter (laser_filters/scan_to_scan_filter_chain) > lidar_node (rplidar_ros/rplidarNode) > robot_state_publisher (robot_state_publisher/robot_state_publisher) > rviz (rviz/rviz) > stretch_driver (stretch_core/stretch_driver) > teleop_twist_keyboard (teleop_twist_keyboard/teleop_twist_keyboard.py) > > auto-starting new master > process[master]: started with pid [24709] > ROS_MASTER_URI=http://localhost:11311 > > setting /run_id to 0803bf94-4e53-11ee-ba9c-fd8d52a91004 > process[rosout-1]: started with pid [24726] > started core service [/rosout] > process[joint_state_publisher-2]: started with pid [24733] > process[robot_state_publisher-3]: started with pid [24734] > process[stretch_driver-4]: started with pid [24735] > process[aggregator_node-5]: started with pid [24736] > process[lidar_node-6]: started with pid [24738] > [WARN] [1694182902.836843482]: The root link base_link has an inertia specified in the URDF, but KDL does not support a root link with an inertia. As a workaround, you can add an extra dummy link to your URDF. > process[laser_filter-7]: started with pid [24743] > process[teleop_twist_keyboard-8]: started with pid [24748] > process[gmapping_record_map-9]: started with pid [24754] > [INFO] [1694182902.879239265]: RPLIDAR running on ROS package rplidar_ros, SDK Version:2.0.0 > process[rviz-10]: started with pid [24758] > [INFO] [rospy.topics]: topicmanager initialized > [INFO] [1694182904.081867]: For use with S T R E T C H (TM) RESEARCH EDITION from Hello Robot Inc. > [INFO] [1694182904.082965]: /stretch_driver started > [INFO] [1694182904.613675]: mode = navigation > [INFO] [1694182904.614839]: /stretch_driver: Changed to mode = navigation > [INFO] [1694182904.616636]: broadcast_odom_tf = True > [INFO] [1694182904.620213]: Loading controller calibration parameters for the head from YAML file named /home/hello-robot/catkin_ws/src/stretch_ros/stretch_core/config/controller_calibration_head.yaml > [INFO] [1694182904.625821]: controller parameters loaded = {'arm_retracted_offset': 0.0025550286250485095, 'pan_angle_offset': -0.012313715472842945, 'pan_looked_left_offset': -0.0012904399890229065, 'tilt_angle_backlash_transition': -0.4, 'tilt_angle_offset': 0.015868523909082964, 'tilt_looking_up_offset': -0.027955338296670372} > [INFO] [1694182904.634759]: head_tilt_calibrated_offset_rad in degrees = 0.9091994470928927 > [INFO] [1694182904.639562]: head_pan_calibrated_offset_rad in degrees = -0.7055239267188396 > [INFO] [1694182904.642274]: head_pan_calibrated_looked_left_offset_rad in degrees = -0.07393676508592083 > [INFO] [1694182904.644588]: head_tilt_backlash_transition_angle_rad in degrees = -22.918311805232932 > [INFO] [1694182904.645893]: head_tilt_calibrated_looking_up_offset_rad in degrees = -1.601722899259652 > [INFO] [1694182904.647128]: arm_calibrated_retracted_offset_m in meters = 0.0025550286250485095 > [INFO] [1694182904.685632]: /stretch_driver rate = 15.0 Hz > [INFO] [1694182904.687069]: /stretch_driver timeout = 0.5 s > [INFO] [1694182904.690840]: /stretch_driver use_fake_mechaduinos = False > [INFO] [1694182904.693612]: /stretch_driver base_frame_id = base_link > [INFO] [1694182904.696899]: /stretch_driver odom_frame_id = odom > > Reading from the keyboard and Publishing to Twist! > --------------------------- > Moving around: > u i o > j k l > m , . > > For Holonomic mode (strafing), hold down the shift key: > --------------------------- > U I O > J K L > M < > > > t : up (+z) > b : down (-z) > > anything else : stop > > q/z : increase/decrease max speeds by 10% > w/x : increase/decrease only linear speed by 10% > e/c : increase/decrease only angular speed by 10% > > CTRL-C to quit > > currently: speed 0.04 turn 0.1 > [ERROR] [1694182906.927481753]: Error, operation time out. RESULT_OPERATION_TIMEOUT! > [lidar_node-6] process has died [pid 24738, exit code 255, cmd /opt/ros/noetic/lib/rplidar_ros/rplidarNode __name:=lidar_node__ log:=/home/hello-robot/.ros/log/0803bf94-4e53-11ee-ba9c-fd8d52a91004/lidar_node-6.log]. > log file: /home/hello-robot/.ros/log/0803bf94-4e53-11ee-ba9c-fd8d52a91004/lidar_node-6*.log > > ``` A reboot always fixes the issue. Just wanted to share if anyone else encounters this as well or to bring it to the developers’ attention. I think the problem may also lie with the rplidar itself, since I have experienced this in other robot setups before, too. ---
**Author:** ![lamsey](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/lamsey/32/177_2.png) [@lamsey](https://forum.hello-robot.com/u/lamsey)\ **Post date:** [September 12, 2023, 4:56pm UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/5 "2023-09-12T16:56:31Z")
I have also noticed this same error. I haven’t updated my robot’s (RE2) software recently, but I did recently begin using the `stretch_scan_matcher`. It seems to randomly fail after restarting the `rplidar.launch` process. I noticed that the lidar also does not stop spinning after I kill the launch file; not sure if it is related. Is there a process that I could kill from the terminal to manually stop the lidar? ---
**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\ **Post date:** [September 12, 2023, 8:00pm UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/6 "2023-09-12T20:00:33Z")
The `stretch_rp_lidar_jog.py --motor_off` command does this. The lidar actually spins by default and stops when a signal is sent. In the past, the rplidar ROS package (maintained by [Slamtec](https://github.com/Slamtec/rplidar_ros)) sent the signal when `rplidar.launch` ended, but in a recent code change, it doesn’t do this anymore. @roboor and @lamsey, thanks for sharing info about these issues. I don’t know much about the Slamtec drivers, but I can try to help here. @roboor, in your case, launching `rplidar.launch` multiple times will cause a `Error, operation time out. RESULT_OPERATION_TIMEOUT!` until you power cycle the robot, right? @lamsey, in your case, `stretch_scan_matcher.launch` stops publishing the odom → base\_link TF after relaunching `rplidar.launch`, right? ---
**Author:** ![roboor](https://avatars.discourse-cdn.com/v4/letter/r/3bc359/32.png) [@roboor](https://forum.hello-robot.com/u/roboor)\ **Post date:** [September 13, 2023, 2:45pm UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/7 "2023-09-13T14:45:49Z")
Yes, but as said, the error is quite rare and unpredictable so far. ---
**Author:** ![lamsey](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/lamsey/32/177_2.png) [@lamsey](https://forum.hello-robot.com/u/lamsey)\ **Post date:** [September 13, 2023, 5:10pm UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/8 "2023-09-13T17:10:36Z")
Sorry for delay, I had to wait for the lidar error to happen again. Running the stop motor command didn’t fix the `rplidar.launch` error. After the error, I checked my `/tf` tree, and there’s still a transform from `odom` to `base_link`. However, nothing is being broadcast on `/pose2D` from the scan matcher. ---
**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\ **Post date:** [September 13, 2023, 6:43pm UTC](https://forum.hello-robot.com/t/lidar-node-process-has-died/760/9 "2023-09-13T18:43:37Z")
Gotcha, thanks. I’ll work on reproducing these issues here and let you guys know if I can.