Joint_trajectory control does not respond to velocity commands

[echoGee]

ISSUE TEMPLATE ver. 1.0.0

Before you open issue, please refer to ROBOTIS e-Manual

1. How to setup?

• U2D2

4. Which Dynamixel have you used?

   • Model Name
     XM540-W150-R

5. Write down the commands you used in order

$ roscore    
$ roslaunch dynamixel_workbench_controllers dynamixel_controllers.launch use_moveit:=true
$ rosrun customcontroller run_controller

6. Please, describe detailed what difficulty

We send a trajectory with joint position and velocity in the joint_trajectory topic. But the servo does not respond to velocity. We have tried setting https://emanual.robotis.com/docs/en/dxl/x/xd540-t150/#operating-mode11 to velocity mode. But still doesn't work

[echoGee]

Any update on this pls ?

[yun-goon]

Hi @echoGee
Sorry for the late reply.
The issue seems related to velocity commands not being processed by the Dynamixel. Here are some steps to resolve the problem:

1. Check Operating Mode

Ensure the Dynamixel is set to Velocity Control Mode. Use the following commands to set and reboot:

id: 1
addr_name: 'Operating_Mode'
value: 1"

rosservice call /dynamixel_workbench/dynamixel_command "command: 'reboot' id: 1"

2. Verify joint_trajectory Topic

Ensure the velocity field in the topic contains valid data:

rostopic echo /joint_trajectory

3. Test Basic Velocity Command

Send a direct velocity command to verify hardware functionality:

rosservice call /dynamixel_workbench/dynamixel_command "command: ''
id: 1
addr_name: 'Goal_Velocity'
value: 100"

4. Check Firmware

Ensure the Dynamixel firmware is updated to the latest version using the Dynamixel Wizard.

5. Provide Details About customcontroller

If the above steps do not resolve the issue, it would be helpful to have more information about the customcontroller code you are using. Specifically:

How it processes velocity commands from the joint_trajectory topic.
Whether it correctly communicates these commands to the Dynamixel.
This additional context will help in identifying whether the problem lies in the control logic or hardware setup. 😊