Unable to obtain joint state handle

[Franklein20]

hello

i'm working on ackerman driving controller, that you developped. i integrated in which has 04 wheels (propulsion and steering)

But at each execution I get this error message. here is also the configuration file controller_manager: ros__parameters: update_rate: 100 # Hz use_sim_time: true

joint_state_broadcaster:
  type: joint_state_broadcaster/JointStateBroadcaster

ackermann_drive:
  type: ackermann_drive_controller/AckermannDriveController

ackermann_drive: ros__parameters: left_wheel_name: "wheel_back_left_joint" right_wheel_name: "wheel_back_right_joint" left_steering_name: "left_wheel_steering_joint" right_steering_name: "right_wheel_steering_joint"

front_steering: true
velocity_rolling_window_size: 10
position_feedback: true
in_chained_mode: false

wheel_separation: 0.297
wheel_radius: 0.05

use_stamped_vel: true

wheel_base: 0.335    
pivot_distance: 0.2  #0.803 

max_steering_speed: 1.5707963267948966
# max_steering_speed: 3.141592653589793
max_steering_angle: 0.7853981633974483

wheel_separation_multiplier: 1.0
left_wheel_radius_multiplier: 1.0
right_wheel_radius_multiplier: 1.0

publish_rate: 50.0
odom_frame_id: odom
base_frame_id: base_link
pose_covariance_diagonal : [0.001, 0.001, 0.0, 0.0, 0.0, 0.01]
twist_covariance_diagonal: [0.001, 0.0, 0.0, 0.0, 0.0, 0.01]

open_loop: false
enable_odom_tf: true

cmd_vel_timeout: 0.5
#publish_limited_velocity: true
#use_stamped_vel: false
#velocity_rolling_window_size: 10

# Velocity and acceleration limits
# Whenever a min_* is unspecified, default to -max_*
linear.x.has_velocity_limits: true
linear.x.has_acceleration_limits: true
linear.x.has_jerk_limits: false
linear.x.max_velocity: 1.0
linear.x.min_velocity: -1.0
linear.x.max_acceleration: 1.0
linear.x.max_jerk: 0.0
linear.x.min_jerk: 0.0

angular.z.has_velocity_limits: true
angular.z.has_acceleration_limits: true
angular.z.has_jerk_limits: false
angular.z.max_velocity: 1.0
angular.z.min_velocity: -1.0
angular.z.max_acceleration: 1.0
angular.z.min_acceleration: -1.0
angular.z.max_jerk: 0.0
angular.z.min_jerk: 0.0

joint_state_broadcaster: ros__parameters: update_rate: 1000 # Hz use_sim_time: true

[khanh93vn]

Hello Franklein20,

Firstly, I would like to apologize for the unstable, buggy software packages. Also, I am sorry I may not be able to help you properly on your issue, as I have stopped working on these codes for quite some time.

However, given the error messages, I'm quite certain that "joint state handle" is the hardware interface from gazebo, so most likely that the issue is not related to joint_state_broadcaster node. Here are some possible causes:

• URDF file
  • Invalid joint name
  • Invalid gazebo plugin tag
• Gazebo
  • Unable to launch properly
  • Unable to spawn from URDF properly
• Launch file
  • Missing arguments
  • Missing node (?)
  • Order of launch (?)

Hope this helps!

[Franklein20]

Thanks for your feedback, On the terminal ,i'm able to see this [gazebo-1] [INFO] [1702299480.460413832] [gazebo_ros2_control]: connected to service!! robot_state_publisher [gazebo-1] [INFO] [1702299480.461012790] [gazebo_ros2_control]: Received urdf from param server, parsing... [gazebo-1] [INFO] [1702299480.466750516] [gazebo_ros2_control]: Loading joint: left_wheel_joint

[gazebo-1] [INFO] [1702299480.466815307] [gazebo_ros2_control]: Loading joint: right_wheel_joint

[gazebo-1] [INFO] [1702299480.466833582] [gazebo_ros2_control]: Loading joint: wheel_back_right_joint

[gazebo-1] [INFO] [1702299480.466849906] [gazebo_ros2_control]: Loading joint: wheel_back_left_joint

[gazebo-1] [INFO] [1702299480.466865744] [gazebo_ros2_control]: Loading joint: left_wheel_steering_joint

[gazebo-1] [INFO] [1702299480.466883521] [gazebo_ros2_control]: Loading joint: right_wheel_steering_joint

[gazebo-1] [INFO] [1702299480.466899173] [gazebo_ros2_control]: Loading joint: right_back_wheel_steering_joint

[gazebo-1] [INFO] [1702299480.466914725] [gazebo_ros2_control]: Loading joint: left_back_wheel_steering_joint

So in gazebo everything seems well. i continues to investigate, if i find something