Discussion - Ros2_Control Overview & Simulation (Making a Mobile Robot Pt 12)

Articulated Robotics Content Discussions
#15

So I’ve been fallowing your tutorial for a project. Thank you BTW. It’s been hard to find Raspberry Pi examples.
Problem is. I ran this part of the tutorial last night and it all seemed to work with exception of a type in my config. The robot started doing flips when set to move forward. Anyways I think I got that solved but now, today when I try to run it the controller manager is not loading… All the sudden it’s just not there any more.
Output:
ros2 run controller_manager spawner diff_cont
[INFO] [1679414845.079311127] [spawner_diff_cont]: Waiting for ‘/controller_manager’ node to exist
[INFO] [1679414847.090650840] [spawner_diff_cont]: Waiting for ‘/controller_manager’ node to exist
[INFO] [1679414849.100639643] [spawner_diff_cont]: Waiting for ‘/controller_manager’ node to exist
[INFO] [1679414851.114171358] [spawner_diff_cont]: Waiting for ‘/controller_manager’ node to exist
[ERROR] [1679414853.122073734] [spawner_diff_cont]: Controller manager not available

Why now? Worked last night. I can’t even list interfaces… Same problem.

#16

Okay… Somehow controller manager mysteriously started working.
Thanks to Niranjan_Rao pointing out the underscore issue, that did make a difference.

But now he is back to doing flips instead of moving forward or reverse. I’m sure I’ll figure it out, obviously a config issue.

#17

HI Josh,
Didn’t find any issues until Ros2_control was introduced.

With gazebo_ros2_control my robot moves only forward and backwards, doesn’t respond the angular velocity command and the /odom frame doesn’t show up in the RVIZ fixed frame selection list.

i have tried it on Foxy and humble. the result is the same.

Any ideas how I can fix this.

1 Like
#18

Hi Josh,
Your tutorial is very helpful. and i want to use ros_control to control my robot with ackermann type instead of your diff.
You can make a video tutorial. I sincerely thank

#19

Further into the investigation i have noticed the odom TF has the below error.

Error: TF NAN_INPUT: Ignoring transform for child_frame_id “base_link” from authority “Authority undetectable” because of a nan value in the transform (-nan -nan 0.000000) (-nan -nan -nan -nan)
at line 278 in /tmp/binarydeb/ros-foxy-tf2-0.13.14/src/buffer_core.cpp
Error: TF DENORMALIZED_QUATERNION: Ignoring transform for child_frame_id “base_link” from authority “Authority undetectable” because of an invalid quaternion in the transform (-nan -nan -nan -nan)

@JoshNewans Can you please help me out on what causes this error and how to resolve it. This has practically stopped me in continuing further in to this wonderful tutorial.

#20

I’m having the same problem. Everything works except the angular velocity

#21

Hello, I have been following along and thanks for your great efforts, everything had been working fine with me until this point. When I tried the laser scan at rviz with ros2_control, the scan moves totally with the robot, the dots move with the orientation of the robot not just wiggle as the small problem but it totally moves. When I switch to gazebo_control everything comes back to normal, not sure what the problem can be?

#22

@Alessandro_Gomez Did you find a solution to this?

#23

I am also facing the same issue. ros2 launch articubot_one launch_sim.launch.py everything is working fine. when i launch ros2 launch articubot_one launch_robot.launch.py i am having controller_manager issues . I did not connect my joystick. and my physical robot has no response.

#24

FYI. In ROS2 Humble, I could perfectly run with just “spawner” not “spawner.py”. It is a little change as you mentioned.

3 Likes
#25

How did you fix the Hardware_interface issues in Humble using GitHub - joshnewans/diffdrive_arduino: A simple ROS Control Hardware Interface for differential drive control of robot whose motors are connected via an Arduino (or similar microcontroller). this Diffdrive_arduino . I was stuck here.

#26

Hi, I facing some issue with gazebo ros2 control package. I followed the instruction for the ros2 control and launch the launch_sim.launch.py everything work perfect but could not connect with gazebo_ros2_control

The error msg:
[gzserver-2] [ERROR] [1691414356.585613673] [gazebo_ros2_control]: Error parsing URDF in gazebo_ros2_control plugin, plugin not active : text not specified in the min tag

because this I wasn’t able to connect with hardware interface

error msg:
ros2 control list_hardware_interfaces
Could not contact service /controller_manager/list_hardware_interfaces

Can you guys help me to figure out what mistake I have made.

Thank you for your help.

#27

Hey Josh,

I am having trouble running the command ros2 run controller_manager spawner.py diff_cont
it is saying that there is no executable found. I have installed and done everything the same as you up until that point.
Any suggestions?

From
Evanston

2 Likes
#28

I figure it out the problem. It was my linux system i just reinstall it an now it working fine

#29

Hello, I am driving the robot in gazebo with teleop twist keyboard but it not moving in rviz.

#30

was working fine launching the controllers manualy but with the launcher

spawner.py-5] [INFO] [1695724540.948537156] [spawner_diff_cont]: Waiting for /controller_manager services
[spawner.py-6] [INFO] [1695724541.043151151] [spawner_joint_broad]: Waiting for /controller_manager services
[gzclient   -3] context mismatch in svga_surface_destroy
[gzclient   -3] context mismatch in svga_surface_destroy
[spawner.py-5] [INFO] [1695724542.965812070] [spawner_diff_cont]: Waiting for /controller_manager services
[spawner.py-6] [INFO] [1695724543.056949421] [spawner_joint_broad]: Waiting for /controller_manager services
[spawner.py-5] [INFO] [1695724544.983464604] [spawner_diff_cont]: Waiting for /controller_manager services
[spawner.py-6] [INFO] [1695724545.078081205] [spawner_joint_broad]: Waiting for /controller_manager services
[spawner.py-5] [INFO] [1695724546.997859933] [spawner_diff_cont]: Waiting for /controller_manager services
[spawner.py-6] [INFO] [1695724547.087982065] [spawner_joint_broad]: Waiting for /controller_manager services
[spawner.py-5] [ERROR] [1695724549.010000553] [spawner_diff_cont]: Controller manager not available
#31

Hi there, I am very thankful for your robot tutorial. Can you let me ask if skipping the tutorial section in video 12a will have much impact on subsequent tutorials. I don’t really need great precision

#32

Can anyone help out with this problem . I am also facing the same issue

#33

@JoshNewans can u help me with this
I download the entire articubot_one code from your Github and am running the command - ros2 launch articubot_one launch_sim.launch.py world:=src/articubot_one/worlds/obstacles.sdf

thabrez@thabrez-Inspiron-15-7000-Gaming:~/dev_ws2$ ros2 launch articubot_one launch_sim.launch.py world:=src/articubot_one/worlds/obstacles.sdf
[INFO] [launch]: All log files can be found below /home/thabrez/.ros/log/2023-11-21-00-51-30-748484-thabrez-Inspiron-15-7000-Gaming-7568
[INFO] [launch]: Default logging verbosity is set to INFO
[ERROR] [launch]: Caught exception in launch (see debug for traceback): executable ‘spawner.py’ not found on the libexec directory ‘/opt/ros/iron/lib/controller_manager’

I checked many times . used source install/setup.bash , correct directory too .
I have ros iron controller manager installed
The spawner.py file also exists in location opt/ros/iron/lib/controller_manager
Have done no modification to original code
newworld.sdf
Can u help me solve this ?? please

#34

Hi @Mohammed_Thabrez
Looks like you are using ros2 iron, this tutorial is for foxy, but it is updated to humble, see https://www.youtube.com/watch?v=qoj5_fVBPII for the update

Try the humble branches of the github repositories.

1 Like