# ROS - Could not obtain transform error in stretch\_funmap

**URL:** <https://forum.hello-robot.com/t/ros-could-not-obtain-transform-error-in-stretch-funmap/122>\
**Category:** Ask\
**Created:** [March 10, 2021, 10:29pm UTC](https://forum.hello-robot.com/t/ros-could-not-obtain-transform-error-in-stretch-funmap/122 "2021-03-10T22:29:27Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Flynn](https://avatars.discourse-cdn.com/v4/letter/f/e56c9b/32.png) [@Flynn](https://forum.hello-robot.com/u/Flynn)\
**Post date:** [March 10, 2021, 10:29pm UTC](https://forum.hello-robot.com/t/ros-could-not-obtain-transform-error-in-stretch-funmap/122/1 "2021-03-10T22:29:27Z")

</div>

Terminal output shown below when stretch\_funmap mapping.launch is run.

**hello-robot@stretch-re1-1033** : **~** $ roslaunch stretch\_funmap mapping.launch

… logging to /home/hello-robot/.ros/log/1d1de53c-81e9-11eb-84ce-94e6f7b75520/roslaunch-stretch-re1-1033-5090.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-re1-1033:33859/](http://stretch-re1-1033:33859/)**

SUMMARY

========

CLEAR PARAMETERS

- /ekf\_se/

PARAMETERS

- /camera/realsense2\_camera/accel\_fps: 63

- /camera/realsense2\_camera/accel\_frame\_id: camera\_accel\_frame

- /camera/realsense2\_camera/accel\_optical\_frame\_id: camera\_accel\_opti…

- /camera/realsense2\_camera/align\_depth: True

- /camera/realsense2\_camera/aligned\_depth\_to\_color\_frame\_id: camera\_aligned\_de…

- /camera/realsense2\_camera/aligned\_depth\_to\_fisheye1\_frame\_id: camera\_aligned\_de…

- /camera/realsense2\_camera/aligned\_depth\_to\_fisheye2\_frame\_id: camera\_aligned\_de…

- /camera/realsense2\_camera/aligned\_depth\_to\_fisheye\_frame\_id: camera\_aligned\_de…

- /camera/realsense2\_camera/aligned\_depth\_to\_infra1\_frame\_id: camera\_aligned\_de…

- /camera/realsense2\_camera/aligned\_depth\_to\_infra2\_frame\_id: camera\_aligned\_de…

- /camera/realsense2\_camera/allow\_no\_texture\_points: True

- /camera/realsense2\_camera/base\_frame\_id: camera\_link

- /camera/realsense2\_camera/calib\_odom\_file:

- /camera/realsense2\_camera/clip\_distance: -2.0

- /camera/realsense2\_camera/color\_fps: 15

- /camera/realsense2\_camera/color\_frame\_id: camera\_color\_frame

- /camera/realsense2\_camera/color\_height: 720

- /camera/realsense2\_camera/color\_optical\_frame\_id: camera\_color\_opti…

- /camera/realsense2\_camera/color\_width: 1280

- /camera/realsense2\_camera/depth\_fps: 15

- /camera/realsense2\_camera/depth\_frame\_id: camera\_depth\_frame

- /camera/realsense2\_camera/depth\_height: 720

- /camera/realsense2\_camera/depth\_optical\_frame\_id: camera\_depth\_opti…

- /camera/realsense2\_camera/depth\_width: 1280

- /camera/realsense2\_camera/device\_type:

- /camera/realsense2\_camera/enable\_accel: True

- /camera/realsense2\_camera/enable\_color: True

- /camera/realsense2\_camera/enable\_depth: True

- /camera/realsense2\_camera/enable\_fisheye1: False

- /camera/realsense2\_camera/enable\_fisheye2: False

- /camera/realsense2\_camera/enable\_fisheye: False

- /camera/realsense2\_camera/enable\_gyro: False

- /camera/realsense2\_camera/enable\_infra1: False

- /camera/realsense2\_camera/enable\_infra2: False

- /camera/realsense2\_camera/enable\_infra: False

- /camera/realsense2\_camera/enable\_pointcloud: False

- /camera/realsense2\_camera/enable\_pose: False

- /camera/realsense2\_camera/enable\_sync: True

- /camera/realsense2\_camera/filters: pointcloud

- /camera/realsense2\_camera/fisheye1\_frame\_id: camera\_fisheye1\_f…

- /camera/realsense2\_camera/fisheye1\_optical\_frame\_id: camera\_fisheye1\_o…

- /camera/realsense2\_camera/fisheye2\_frame\_id: camera\_fisheye2\_f…

- /camera/realsense2\_camera/fisheye2\_optical\_frame\_id: camera\_fisheye2\_o…

- /camera/realsense2\_camera/fisheye\_fps: 30

- /camera/realsense2\_camera/fisheye\_frame\_id: camera\_fisheye\_frame

- /camera/realsense2\_camera/fisheye\_height: 480

- /camera/realsense2\_camera/fisheye\_optical\_frame\_id: camera\_fisheye\_op…

- /camera/realsense2\_camera/fisheye\_width: 640

- /camera/realsense2\_camera/gyro\_fps: 200

- /camera/realsense2\_camera/gyro\_frame\_id: camera\_gyro\_frame

- /camera/realsense2\_camera/gyro\_optical\_frame\_id: camera\_gyro\_optic…

- /camera/realsense2\_camera/imu\_optical\_frame\_id: camera\_imu\_optica…

- /camera/realsense2\_camera/infra1\_frame\_id: camera\_infra1\_frame

- /camera/realsense2\_camera/infra1\_optical\_frame\_id: camera\_infra1\_opt…

- /camera/realsense2\_camera/infra2\_frame\_id: camera\_infra2\_frame

- /camera/realsense2\_camera/infra2\_optical\_frame\_id: camera\_infra2\_opt…

- /camera/realsense2\_camera/infra\_fps: 30

- /camera/realsense2\_camera/infra\_height: 480

- /camera/realsense2\_camera/infra\_width: 640

- /camera/realsense2\_camera/initial\_reset: False

- /camera/realsense2\_camera/json\_file\_path:

- /camera/realsense2\_camera/linear\_accel\_cov: 0.01

- /camera/realsense2\_camera/odom\_frame\_id: camera\_odom\_frame

- /camera/realsense2\_camera/pointcloud\_texture\_index: 0

- /camera/realsense2\_camera/pointcloud\_texture\_stream: RS2\_STREAM\_COLOR

- /camera/realsense2\_camera/pose\_frame\_id: camera\_pose\_frame

- /camera/realsense2\_camera/pose\_optical\_frame\_id: camera\_pose\_optic…

- /camera/realsense2\_camera/publish\_odom\_tf: True

- /camera/realsense2\_camera/publish\_tf: True

- /camera/realsense2\_camera/rosbag\_filename:

- /camera/realsense2\_camera/serial\_no:

- /camera/realsense2\_camera/tf\_publish\_rate: 0.0

- /camera/realsense2\_camera/topic\_odom\_in: odom\_in

- /camera/realsense2\_camera/unite\_imu\_method:

- /camera/realsense2\_camera/usb\_port\_id:

- /d435i\_configure/initial\_mode: High Accuracy

- /ekf\_se/acceleration\_gains: [0.8, 0.0, 0.0, 0…

- /ekf\_se/acceleration\_limits: [1.3, 0.0, 0.0, 0…

- /ekf\_se/base\_link\_frame: base\_link

- /ekf\_se/control\_config: [True, False, Fal…

- /ekf\_se/control\_timeout: 0.2

- /ekf\_se/debug: False

- /ekf\_se/debug\_out\_file: /path/to/debug/fi…

- /ekf\_se/deceleration\_gains: [1.0, 0.0, 0.0, 0…

- /ekf\_se/deceleration\_limits: [1.3, 0.0, 0.0, 0…

- /ekf\_se/frequency: 15

- /ekf\_se/imu0: /imu/data

- /ekf\_se/imu0\_config: [False, False, Fa…

- /ekf\_se/imu0\_differential: True

- /ekf\_se/imu0\_nodelay: False

- /ekf\_se/imu0\_queue\_size: 1

- /ekf\_se/imu0\_relative: True

- /ekf\_se/imu0\_remove\_gravitational\_acceleration: True

- /ekf\_se/initial\_estimate\_covariance: [‘1e-9’, 0, 0, 0,…

- /ekf\_se/map\_frame: map

- /ekf\_se/odom0: /odom

- /ekf\_se/odom0\_config: [True, True, True…

- /ekf\_se/odom0\_differential: True

- /ekf\_se/odom0\_nodelay: False

- /ekf\_se/odom0\_queue\_size: 1

- /ekf\_se/odom0\_relative: False

- /ekf\_se/odom\_frame: odom

- /ekf\_se/print\_diagnostics: True

- /ekf\_se/process\_noise\_covariance: [0.05, 0, 0, 0, 0…

- /ekf\_se/publish\_acceleration: False

- /ekf\_se/publish\_tf: False

- /ekf\_se/sensor\_timeout: 0.2

- /ekf\_se/stamped\_control: False

- /ekf\_se/transform\_time\_offset: 0.0

- /ekf\_se/transform\_timeout: 0.0

- /ekf\_se/two\_d\_mode: True

- /ekf\_se/use\_control: False

- /ekf\_se/world\_frame: odom

- /funmap/debug\_directory: /home/hello-robot…

- /imu\_filter\_node/fixed\_frame: map

- /imu\_filter\_node/use\_mag: False

- /joint\_state\_publisher/rate: 15.0

- /joint\_state\_publisher/source\_list: [’/stretch/joint\_…

- /laser\_scan\_matcher\_node/fixed\_frame: odom

- /laser\_scan\_matcher\_node/max\_angular\_correction\_deg: 20.0

- /laser\_scan\_matcher\_node/max\_iterations: 10

- /laser\_scan\_matcher\_node/max\_linear\_correction: 0.2

- /laser\_scan\_matcher\_node/use\_imu: False

- /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: \<?xml version="1…

- /robot\_state\_publisher/publish\_frequency: 15.0

- /rosdistro: melodic

- /rosversion: 1.14.9

- /stretch\_driver/broadcast\_odom\_tf: False

- /stretch\_driver/controller\_calibration\_file: /home/hello-robot…

- /stretch\_driver/fail\_out\_of\_range\_goal: False

- /stretch\_driver/rate: 25.0

- /stretch\_driver/timeout: 0.5

NODES

/

d435i\_accel\_correction (stretch\_core/d435i\_accel\_correction)

d435i\_configure (stretch\_core/d435i\_configure)

d435i\_frustum\_visualizer (stretch\_core/d435i\_frustum\_visualizer)

ekf\_se (robot\_localization/ekf\_localization\_node)

funmap (stretch\_funmap/funmap)

imu\_filter\_node (imu\_filter\_madgwick/imu\_filter\_node)

joint\_state\_publisher (joint\_state\_publisher/joint\_state\_publisher)

keyboard\_teleop (stretch\_core/keyboard\_teleop)

laser\_scan\_matcher\_node (laser\_scan\_matcher/laser\_scan\_matcher\_node)

lidar\_node (rplidar\_ros/rplidarNode)

robot\_state\_publisher (robot\_state\_publisher/robot\_state\_publisher)

rviz (rviz/rviz)

stretch\_driver (stretch\_core/stretch\_driver)

/camera/

realsense2\_camera (nodelet/nodelet)

realsense2\_camera\_manager (nodelet/nodelet)

**ROS\_MASTER\_URI=http://localhost:11311**

**process[d435i\_accel\_correction-1]: started with pid [5106]**

**process[camera/realsense2\_camera\_manager-2]: started with pid [5107]**

**process[camera/realsense2\_camera-3]: started with pid [5108]**

**process[d435i\_configure-4]: started with pid [5109]**

**process[d435i\_frustum\_visualizer-5]: started with pid [5110]**

**process[joint\_state\_publisher-6]: started with pid [5116]**

**process[robot\_state\_publisher-7]: started with pid [5117]**

[INFO] [1615415149.036122880]: Initializing nodelet with 8 worker threads.

**process[stretch\_driver-8]: started with pid [5133]**

**process[funmap-9]: started with pid [5134]**

**process[imu\_filter\_node-10]: started with pid [5136]**

[WARN] [1615415149.085321598]: 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[ekf\_se-11]: started with pid [5141]**

[INFO] [1615415149.123052722]: Starting ImuFilter

[INFO] [1615415149.128908226]: Using dt computed from message headers

[INFO] [1615415149.129006335]: The gravity vector is kept in the IMU message.

**process[lidar\_node-12]: started with pid [5146]**

**process[laser\_scan\_matcher\_node-13]: started with pid [5152]**

[INFO] [1615415149.164603383]: Imu filter gain set to 0.100000

[INFO] [1615415149.164668389]: Gyro drift bias set to 0.000000

[INFO] [1615415149.164684459]: Magnetometer bias values: 0.000000 0.000000 0.000000

**process[keyboard\_teleop-14]: started with pid [5158]**

[INFO] [1615415149.209308849]: RPLIDAR running on ROS package rplidar\_ros. SDK Version:1.7.0

**process[rviz-15]: started with pid [5162]**

[INFO] [1615415149.235879517]: Starting LaserScanMatcher

qt.qpa.screen: QXcbConnection: Could not connect to display

Could not connect to any X display.

[rviz-15] process has died [pid 5162, exit code 1, cmd /opt/ros/melodic/lib/rviz/rviz -d /home/hello-robot/catkin\_ws/src/stretch\_ros/stretch\_funmap/rviz/stretch\_mapping.rviz \_\_name:=rviz \_\_log:=/home/hello-robot/.ros/log/1d1de53c-81e9-11eb-84ce-94e6f7b75520/rviz-15.log].

log file: /home/hello-robot/.ros/log/1d1de53c-81e9-11eb-84ce-94e6f7b75520/rviz-15\*.log

[WARN] [1615415149.303091728]: Both imu0\_differential and imu0\_relative were set to true. Using differential mode.

[INFO] [1615415149.367271036]: RealSense ROS v2.2.17

[INFO] [1615415149.367697785]: Built with LibRealSense v2.38.1

[INFO] [1615415149.367937514]: Running with LibRealSense v2.38.1

[INFO] [1615415149.436200223]:

[INFO] [1615415149.516972]: /d435i\_accel\_correction started

[INFO] [1615415149.700663364]: Device with serial number 944122072492 was found.

[INFO] [1615415149.700970352]: Device with physical ID 2-2-5 was found.

[INFO] [1615415149.701306576]: Device with name Intel RealSense D435I was found.

[INFO] [1615415149.702798126]: Device with port number 2-2 was found.

[INFO] [1615415149.705636513]: getParameters…

[INFO] [1615415149.773330685]: setupDevice…

[INFO] [1615415149.773479016]: JSON file is not provided

[INFO] [1615415149.773577220]: ROS Node Namespace: camera

[INFO] [1615415149.773667475]: Device Name: Intel RealSense D435I

[INFO] [1615415149.773748419]: Device Serial No: 944122072492

[INFO] [1615415149.773826710]: Device physical port: 2-2-5

[INFO] [1615415149.773902481]: Device FW version: 05.12.08.200

[INFO] [1615415149.773978856]: Device Product ID: 0x0B3A

[INFO] [1615415149.774056065]: Enable PointCloud: On

[INFO] [1615415149.774132293]: Align Depth: On

[INFO] [1615415149.774209923]: Sync Mode: On

[INFO] [1615415149.774394329]: Device Sensors:

[INFO] [1615415149.804250957]: Stereo Module was found.

[INFO] [1615415149.831247008]: RGB Camera was found.

[INFO] [1615415149.831668698]: Motion Module was found.

[INFO] [1615415149.831735091]: Add Filter: pointcloud

[INFO] [1615415149.832570730]: num\_filters: 1

[INFO] [1615415149.832609918]: Setting Dynamic reconfig parameters.

[INFO] [1615415149.846137]: /d435i\_frustum\_visualizer started

[INFO] [1615415150.001644]: /d435i\_configure started

hwmon command 0x7d( 0 0 0 0 ) failed (response -21= No data to return)

[INFO] [1615415150.212122736]: Done Setting Dynamic reconfig parameters.

[INFO] [1615415150.213160357]: depth stream is enabled - width: 1280, height: 720, fps: 15, Format: Z16

[INFO] [1615415150.214640265]: color stream is enabled - width: 1280, height: 720, fps: 15, Format: RGB8

[INFO] [1615415150.218132919]: setupPublishers…

[INFO] [1615415150.220983835]: Expected frequency for depth = 15.00000

[INFO] [1615415150.252947748]: Expected frequency for color = 15.00000

[INFO] [1615415150.277037278]: Expected frequency for aligned\_depth\_to\_color = 15.00000

[INFO] [1615415150.297096924]: setupStreams…

[INFO] [1615415150.307932235]: insert Depth to Stereo Module

[INFO] [1615415150.308007811]: insert Color to RGB Camera

[INFO] [1615415150.308044954]: insert Accel to Motion Module

[INFO] [1615415150.311907]: initial\_mode = High Accuracy

[INFO] [1615415150.330809]: Set D435i to High Accuracy mode

[INFO] [1615415150.404864807]: SELECTED BASE:Depth, 0

[INFO] [1615415150.412708650]: RealSense Node Is Up!

[INFO] [1615415150.505921]: /keyboard\_teleop started

[INFO] [1615415150.507316]: For use with S T R E T C H ™ RESEARCH EDITION from Hello Robot Inc.

[INFO] [1615415150.508247]: /stretch\_driver started

[INFO] [1615415150.510100]: mode = navigation

[INFO] [1615415150.511873]: broadcast\_odom\_tf = False

[INFO] [1615415150.513746]: 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] [1615415150.516210]: controller parameters loaded = {‘tilt\_looking\_up\_offset’: -0.007991362557756053, ‘arm\_retracted\_offset’: 0.003431998628653808, ‘tilt\_angle\_backlash\_transition’: -0.4, ‘tilt\_angle\_offset’: -0.11863479457900214, ‘pan\_angle\_offset’: 0.03578660451542777, ‘pan\_looked\_left\_offset’: -0.0017655938546597139}

[INFO] [1615415150.524021]: self.head\_tilt\_calibrated\_offset\_rad in degrees = -6.79727303278

[INFO] [1615415150.525171]: self.head\_pan\_calibrated\_offset\_rad in degrees = 2.05042140184

[INFO] [1615415150.526564]: self.head\_pan\_calibrated\_looked\_left\_offset\_rad in degrees = -0.101161076206

[INFO] [1615415150.527843]: self.head\_tilt\_backlash\_transition\_angle\_rad in degrees = -22.9183118052

[INFO] [1615415150.528891]: self.head\_tilt\_calibrated\_looking\_up\_offset\_rad in degrees = -0.457871347118

[INFO] [1615415150.529967]: self.wrist\_extension\_calibrated\_retracted\_offset\_m in meters = 0.00343199862865

[INFO] [1615415150.537275]: /stretch\_driver rate = 25.0 Hz

[INFO] [1615415150.538120]: /stretch\_driver timeout = 0.5 s

[INFO] [1615415150.539677]: /stretch\_driver use\_fake\_mechaduinos = False

[INFO] [1615415150.540556]: /stretch\_driver base\_frame\_id = base\_link

[INFO] [1615415150.541393]: /stretch\_driver odom\_frame\_id = odom

Traceback (most recent call last):

File “/home/hello-robot/catkin\_ws/src/stretch\_ros/stretch\_funmap/nodes/funmap”, line 39, in

import stretch\_funmap.merge\_maps as mm

File “/home/hello-robot/catkin\_ws/src/stretch\_ros/stretch\_funmap/src/stretch\_funmap/merge\_maps.py”, line 13, in

import navigation\_planning as na

File “/home/hello-robot/catkin\_ws/src/stretch\_ros/stretch\_funmap/src/stretch\_funmap/navigation\_planning.py”, line 5, in

import cython\_min\_cost\_path as cm

ImportError: No module named cython\_min\_cost\_path

[funmap-9] process has died [pid 5134, exit code 1, cmd /home/hello-robot/catkin\_ws/src/stretch\_ros/stretch\_funmap/nodes/funmap \_\_name:=funmap \_\_log:=/home/hello-robot/.ros/log/1d1de53c-81e9-11eb-84ce-94e6f7b75520/funmap-9.log].

log file: /home/hello-robot/.ros/log/1d1de53c-81e9-11eb-84ce-94e6f7b75520/funmap-9\*.log

[WARN] [1615415151.212657630]: Hardware Notification:RT IC2 Config error,1.61542e+12,Error,Hardware Error

[ERROR] [1615415151.212715628]: Performing Hardware Reset.

2021-03-10 14:25:51,582 - stretch-re1-1033 - robot - INFO - Starting up Robot

RPLIDAR S/N: 808B9A87C5E392D2A5E492F8105E316C

[INFO] [1615415151.721511541]: Firmware Ver: 1.25

[INFO] [1615415151.721533042]: Hardware Rev: 5

[INFO] [1615415151.722950379]: RPLidar health status : 0

2021-03-10 14:25:52,007 - stretch-re1-1033 - robot.base - INFO - Fast motion turned off

[INFO] [1615415152.111077]: /stretch\_driver: Changed to mode = navigation

[INFO] [1615415152.135311183]: First IMU message received.

[WARN] [1615415152.135621895]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

[INFO] [1615415152.205797]: Node /keyboard\_teleop connected to /stop\_the\_robot service.

[INFO] [1615415152.210042]: Node /keyboard\_teleop waiting to connect to /funmap/trigger\_head\_scan.

[WARN] [1615415152.212903816]: Hardware Notification:Motion Module force pause,1.61542e+12,Error,Hardware Error

[INFO] [1615415152.322797615]: current scan mode: Boost, max\_distance: 12.0 m, Point number: 8.0K , angle\_compensate: 2

[WARN] [1615415154.143050929]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

[ERROR] [1615415154.731811096]: The device has been disconnected!

[INFO] [1615415154.778606081]: Checking new devices…

[INFO] [1615415154.778639938]:

[INFO] [1615415155.104675785]: Device with serial number 944122072492 was found.

[INFO] [1615415155.104716964]: Device with physical ID 2-2-6 was found.

[INFO] [1615415155.104736965]: Device with name Intel RealSense D435I was found.

[INFO] [1615415155.105134381]: Device with port number 2-2 was found.

[INFO] [1615415155.106302508]: getParameters…

[INFO] [1615415155.139577219]: setupDevice…

[INFO] [1615415155.139603789]: JSON file is not provided

[INFO] [1615415155.139624949]: ROS Node Namespace: camera

[INFO] [1615415155.139644061]: Device Name: Intel RealSense D435I

[INFO] [1615415155.139657852]: Device Serial No: 944122072492

[INFO] [1615415155.139671757]: Device physical port: 2-2-6

[INFO] [1615415155.139680750]: Device FW version: 05.12.08.200

[INFO] [1615415155.139691121]: Device Product ID: 0x0B3A

[INFO] [1615415155.139702948]: Enable PointCloud: On

[INFO] [1615415155.139714979]: Align Depth: On

[INFO] [1615415155.139726685]: Sync Mode: On

[INFO] [1615415155.139747098]: Device Sensors:

[INFO] [1615415155.163603653]: Stereo Module was found.

[INFO] [1615415155.180240722]: RGB Camera was found.

[INFO] [1615415155.180431715]: Motion Module was found.

[INFO] [1615415155.180452756]: Add Filter: pointcloud

[INFO] [1615415155.180881586]: num\_filters: 1

[INFO] [1615415155.180895467]: Setting Dynamic reconfig parameters.

hwmon command 0x7d( 0 0 0 0 ) failed (response -21= No data to return)

[INFO] [1615415155.630491891]: Done Setting Dynamic reconfig parameters.

[INFO] [1615415155.631220365]: depth stream is enabled - width: 1280, height: 720, fps: 15, Format: Z16

[INFO] [1615415155.632225121]: color stream is enabled - width: 1280, height: 720, fps: 15, Format: RGB8

[INFO] [1615415155.635262202]: setupPublishers…

[INFO] [1615415155.636847137]: Expected frequency for depth = 15.00000

[INFO] [1615415155.655650500]: Expected frequency for color = 15.00000

[INFO] [1615415155.668357700]: Expected frequency for aligned\_depth\_to\_color = 15.00000

[INFO] [1615415155.684419634]: setupStreams…

[INFO] [1615415155.694993241]: insert Depth to Stereo Module

[INFO] [1615415155.695048364]: insert Color to RGB Camera

[INFO] [1615415155.695076094]: insert Accel to Motion Module

[INFO] [1615415155.817847138]: SELECTED BASE:Depth, 0

[INFO] [1615415155.824788454]: RealSense Node Is Up!

[WARN] [1615415156.171691218]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

[WARN] [1615415157.631188135]: Hardware Notification:Depth stream start failure,1.61542e+12,Error,Hardware Error

[WARN] [1615415158.192549924]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

[WARN] [1615415160.201589209]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

[WARN] [1615415162.214846048]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

[WARN] [1615415164.234055622]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

[WARN] [1615415166.240788355]: Could not obtain transform from imu\_mobile\_base to base\_link. Error was Could not find a connection between ‘base\_link’ and ‘imu\_mobile\_base’ because they are not part of the same tree.Tf has two or more unconnected trees.

---

<div class="post-metadata">

**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:** [March 11, 2021, 2:23am UTC](https://forum.hello-robot.com/t/ros-could-not-obtain-transform-error-in-stretch-funmap/122/2 "2021-03-11T02:23:45Z")

</div>

Hi @Flynn, welcome to the forum! Looks like an ImportError is the root cause of this issue. If you’ve created or a new user or re-cloned stretch\_ros, you can compile the Cython/Numba using the following commands:

```auto
# ensure latest stretch_ros code
cd ~/catkin_ws/src/stretch_ros
git pull

# compile Cython code
cd ~/catkin_ws/src/stretch_ros/stretch_funmap/src/stretch_funmap
./compile_cython_code.sh

```

This will generate the cython\_min\_cost\_path module and prevent the `ImportError: No module named cython_min_cost_path` error from occuring.

---

<div class="post-metadata">

**Author:** ![Flynn](https://avatars.discourse-cdn.com/v4/letter/f/e56c9b/32.png) [@Flynn](https://forum.hello-robot.com/u/Flynn)\
**Post date:** [March 11, 2021, 7:57am UTC](https://forum.hello-robot.com/t/ros-could-not-obtain-transform-error-in-stretch-funmap/122/3 "2021-03-11T07:57:12Z")

</div>

Thanks very much! That’s done the trick.