Add InverseKinematics class

[Giulero]

This pull request introduces an inverse kinematics module to the adam.casadi package. The changes include the addition of a new InverseKinematics class, which provides functionality for solving various inverse kinematics problems, such as position, orientation, and pose targets, as well as constraints between frames. The most important changes are detailed below.

New Module Addition

• src/adam/casadi/inverse_kinematics.py: Added the InverseKinematics class, which includes methods for defining targets (position, orientation, pose), updating targets, adding constraints (e.g., ball, hinge, fixed), setting initial guesses, solving the optimization problem, and retrieving the solution. This class leverages CasADi for optimization and symbolic computation.

Package Integration

• src/adam/casadi/__init__.py: Imported the new InverseKinematics module into the adam.casadi package, making it accessible as part of the package's API.

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📚 Documentation preview 📚: https://adam-docs--128.org.readthedocs.build/en/128/

[traversaro]

cc @STaliani this can be useful for you as well!

[traversaro]

How can it not a constraint if I am calling it with add_ball_constraint ? We historically had a huge confusion between constraints and tasks in iDynTree, but probably we can try to avoid it here, for example using a different term (as_optimization_constraint or something similar?).

[Giulero]

Makes sense!
What do you think about something like ik.add_ball_constraint(frame_1, frame_2, as_soft_constraint=True)?

[traversaro]

Ok, but probably we may want to have an argument with a similar name in add_target to avoid confusion.

[Giulero]

I could add to the add_target method an input called as_soft_constraint as well.

[Giulero]

Updated to

ik.add_target("l_sole", target_type=TargetType.POSE, as_soft_constraint=True, weight=1.0)
ik.add_ball_constraint(frame_1, frame_2, as_soft_constraint=True)

[Copilot]

Pull Request Overview

This PR adds a new inverse kinematics solver to the adam.casadi package, enabling users to define and solve IK problems with position, orientation, pose targets, and frame‐to‐frame constraints.

• Introduces InverseKinematics class in inverse_kinematics.py with methods for adding targets, constraints, setting initial guesses, and solving via CasADi.
• Updates package exports to include the new class and its TargetType.
• Adjusts CI and packaging to add the new liecasadi dependency.
• Expands README.md with installation tweaks and an IK usage example.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/adam/casadi/inverse_kinematics.py	New IK solver implementation with targets & constraints
src/adam/casadi/init.py	Export InverseKinematics and TargetType
pyproject.toml	Adds liecasadi to test dependencies
ci_env_win.yml & ci_env.yml	Includes liecasadi in CI environment
README.md	Updates installation commands and adds IK usage docs

Comments suppressed due to low confidence (2)

src/adam/casadi/inverse_kinematics.py:243

• [nitpick] The parameter as_constraint here is inconsistent with as_soft_constraint used by add_frames_constraint; consider renaming to as_soft_constraint or harmonizing naming for clarity.

    def add_fixed_constraint(

pyproject.toml:51

• The liecasadi dependency is only added under the test extra; since inverse_kinematics.py imports it at runtime, it should be included in the main or 'all' dependencies to avoid missing package errors.

  "liecasadi",

[Copilot]

[nitpick] Avoid using print for diagnostic messages in library code; consider using a logger or removing this statement.

Suggested change

	print(
	logger.debug(

[traversaro]

I fear this sentence is misleading. "If True, adds the target as a cost term instead of a constraint." seems to indicate this parameter is False by default, while it is actually True by default, perhaps this can be made more clear?

[Giulero]

Totally true! Updated all the args descriptions

[traversaro]

Minor comments.

[Giulero]

Thanks a lot @traversaro! Addressed the comments.