Add velocity limits component (#2664)

[mo-zaghloul]

🎉 New feature

Closes #2664

Summary

This PR introduces the JointVelocityLimits component and starts integrating it into the Joint class and physics system. However, I need guidance on completing the physics implementation.

Changes in this PR

• Added JointVelocityLimits.hh component to store joint velocity limits.
• Integrated the component into Joint.cc.
• Started integrating it into Physics.cc (incomplete, need guidance).

Test it

The component has been added, but since the physics integration is incomplete, full testing isn't possible yet. Once I receive guidance on the correct approach, I will add appropriate tests.

Guidance Needed

I am currently stuck on integrating velocity limits correctly into the physics system. Specifically, I would appreciate guidance on:

• The best approach to retrieve and apply velocity limits within the physics update loop.
• Ensuring that the component interacts correctly with the existing joint properties in simulation.

Checklist

• Signed all commits for DCO
• Added new component JointVelocityLimits
• Completed physics system integration
• Added tests (Will finalize after physics integration)
• Updated documentation (Will finalize after implementation)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

[ahcorde]

remove this file

[ahcorde]

Suggested change

	* Copyright (C) 2021 Open Source Robotics Foundation
	* Copyright (C) 2025 Open Source Robotics Foundation

[mo-zaghloul]

Hi @ahcorde,

Thanks for the review! I’ve made the changes as suggested.

I need some help with integrating joint velocity limits into the physics system. I’ve created the JointVelocityLimits component, but I’m unsure about how to properly connect it within Joint.cc and the physics system to ensure it works as expected. Could you provide some guidance on how to approach this integration?

Looking forward to your feedback!

Thanks!

[iche033]

I think you can just get this information from the JointAxis component, e.g.

auto jointAxis = _ecm.Component<components::JointAxis>(this->dataPtr->id);
if (jointAxis)
{
  return jointAxis->Data().MaxVelocity();
}

For joint velocity, there is no lower or upper limit, but only just one velocity limit field

[ahcorde]

@iche033 can you review it one more time?

[iche033]

left a comment on the return type of the VelocityLimits function

[iche033]

there is a compile error here. The declaration in the header is std::optional<std::vector<gz::math::Vector2d> but it is std::optional<gz::math::Vector2d> here.

I think it should be std::optional<std::vector<gz::math::Vector2d> so that it is consistent with the JointVelocityLimitsCmd component.

On the other hand, the function returns jointAxis->Data().MaxVelocity() which is just a double. So we'll need to change it to return a vector of gz::math::Vector2d, something like (untested):

return {gz::math::Vector2d(-jointAxis->Data().MaxVelocity(), 
        jointAxis->Data().MaxVelocity())};

[azeey]

Hi @mo-zaghloul, any progress on this?