MPPI dynamic parameter not working with vx_max

[Huyhust13]

Bug report

Required Info:

• Operating System: Ubuntu 22.04
• ROS2 Version: Humble
• Version or commit hash: 150dd6beb50aee502ada8935cee23d7160a40f57
• DDS implementation: mw_cyclonedds_cpp

Expected behavior

I set vx_max = 0.5 in file parameter, then when it is running, I change the vx_max to 0.3. I use parameter get to show param, it shows vx_max = 0.3 but the robot runs with vx = 0.5.

[SteveMacenski]

Correct, we update settings.base_constraints with parameter inputs, not settings.constraints which is what is used for clipping (https://github.com/open-navigation/navigation2/blob/main/nav2_mppi_controller/src/optimizer.cpp#L76). This is done to decouple the parameters and allow for dynamic updates of the velocities via the speed limiter API (https://github.com/open-navigation/navigation2/blob/main/nav2_mppi_controller/src/optimizer.cpp#L419-L444) so we can store the "true" max velocity for setting percentage adjustments with respect to.

We do however sync them up when the controller is reset (https://github.com/open-navigation/navigation2/blob/main/nav2_mppi_controller/src/optimizer.cpp#L126) which happens when parameter updates are made in main https://github.com/open-navigation/navigation2/blob/main/nav2_mppi_controller/src/optimizer.cpp#L89.

It looks like that might need the following added to Humble's reset() method like we have in main. Can you test to verify that does what you need it to do then open a PR?

  settings_.constraints = settings_.base_constraints;

https://github.com/open-navigation/navigation2/commit/569f1672609c22bc52c4c4c486818fde3bd99646

[Huyhust13]

Thank for your replying @SteveMacenski. I'll do test.

[Huyhust13]

It's correct, it works now @SteveMacenski Thank you very much for your help.