Releases | Open Source Science

pin-pink - v3.4.0

This release adds the JointVelocityTask whose aim is to track a reference joint-velocity vector via $\arg\minv \Vert v{ref} - v \Vert^2$. This task can be used, for instance, if a reference velocity is computed by other means (optimal control, reinforcement-learned policy, ...), and the differential IK acts as a constraint-enforcing filter. An example illustrates this with a Unitree Z1 tracking a trajectory that would violate joint limits:

https://github.com/user-attachments/assets/3c0e221b-4180-4c8c-9ced-1cc61448c2ad

(In the example, joint limits don't prevent self-collisions when the arm is folded on itself.)

Added

Task: JointVelocityTask for tracking a reference joint-velocity trajectory

Fixed

Save problem instance in NoSolutionFound exception

Removed

Remove unused attribute of SelfCollisionBarrier

- Python
Published by stephane-caron 7 months ago

pin-pink - v3.3.0

This version adds (1) a constraints argument to solve_ik, to enforce tasks as QP equality constraints rather than in the objective function, and (2) the omniwheel task, which is like a rolling task but allows lateral motion.

Note that, internally, exceptions have been grouped into the pink.exceptions submodule. We don't count this as an API-breaking change, although strictly speaking it is :blush:, as the expected way to handle Pink exceptions is to catch PinkError.

Thanks to @jorisv for contributing to this release :+1:

Added

CICD: Unit test fixture for the rolling task
CICD: Unit test fixture for the omniwheel task
Introduce constraints to enforce tasks as QP equality constraints
Task: Add missing task __repr__ functions
Task: Omniwheel task, like a rolling task but allowing lateral motion

Changed

CICD: Switch to Pixi for code coverage, documentation, linting and testing
Move pink.barriers.exceptions to pink.exceptions
Move pink.tasks.exceptions to pink.exceptions
Task: Make __repr__ of base class abstract to ensure tasks define their own
docs: Refactor Tasks page and update references
examples: Update installation hints when example dependencies are missing

Fixed

CICD: Improve Pixi configuration (thanks to @jorisv)
Task: Fix damping task when the robot model has a mobile root joint
Task: Report LM damping in CoM task representation

- Python
Published by stephane-caron 9 months ago

pin-pink - v3.2.0

This release introduces the NoSolutionFound exception (previously an AssertionError), and makes a stricter check that the QP solver reports successfully converging to a solution. It is still possible to catch cases where the solver converged (but not to a solution) as follows:

py try: velocity = solve_ik(configuration, tasks, dt, solver=solver) except NoSolutionFound as exn: if exn.results.x is not None: # QP solver converged but not to a solution velocity = exn.results.x raise exn

This release also removes an unrequired dependency on quadprog. This solver is still great for IK, but we cannot distribute it with Pink (permissive license: Apache-2.0) as it is licensed under the GPL-2.0. Feel free to install and use it on your own!

Thanks to @ashwinvkNV and @peterd-NV for helping address this licensing issue :+1:

Added

Add NoSolutionFound exception
Add open keyword argument to start_meshcat_visualizer
examples: Detail that quadprog works best on Stretch examples
examples: Installation instruction for loop-rate-limiters
examples: Switch to DAQP solvers in examples where it works well
examples: Switch to ProxQP on JVRC-1 example
examples: Switch to ProxQP on one-dof configuration limit example

Changed

CICD: Switch from tox to Anaconda environments
CICD: Update QP solvers used in unit tests
CICD: Update checkout action to v4
Raise custom NoSolutionFound rather than AssertionError in solve_ik
Update supported Python versions

Fixed

CICD: Update unit test for self-collision barrier

Removed

Remove dependency on quadprog (thanks to @peterd-NV)

- Python
Published by stephane-caron 10 months ago

pin-pink - v3.1.0

This release adds the RollingTask for rolling without slipping. Here is an example:

Wheeled biped: Upkie rolling without slipping

https://github.com/user-attachments/assets/18ae0b68-21a2-44ec-af48-1d8ab4a7e658

Added

Example: Upkie rolling without slipping on a horizontal floor
Task: RollingTask for rolling without slipping on a plane

Changed

Rename "end-effector to target" example to "inverse kinematics UR10"
Update icon of documentation website

Fixed

Update documentation Sphinx and theme versions
Fix Jacobian of SelfCollisionBarrier for floating-base robots

- Python
Published by stephane-caron over 1 year ago

pin-pink - v3.0.0

This major release adds Control Barrier Functions developed by @domrachev03 and @simeon-ned :+1: Examples of what we can do with barriers include:

Arm: UR5: with joints and end effector limits
Humanoid: G1: G1 humanoid squatting via a CoM task
Quadruped: Go2: Go 2 squatting with floating base position limits
Dual Arms: Yumi: self-collision avoidance with spheres
Dual Arms: Iiwa: whole-body self-collision avoidance

https://github.com/domrachev03/pink/assets/28687492/d64163b6-399f-4bbf-ac50-1135fa69c2da

Another API-breaking change to the library is that limits are now optional and can be extended (for instance with the new acceleration limit) or disabled. New limits and tasks include:

Limit: AccelerationLimit
Task: ComTask for center-of-mass tracking (thanks to @simeon-ned)
Task: LowAccelerationTask for smoother velocities.

Check out the full changelog below for other changes and fixes. May the Motion be with you!

Added

Breaking: Updated the logic for handling the joint limits:
- Add a limits argument to build_ik and solve_ik
- The check_limits method now includes an optional safety_break argument to control whether execution should stop on exception.
- The solve_ik function now includes the safety_break that is forwarded to check_limits.
Control Barrier Functions, namely: (thanks to @domrachev03 and @simeon-ned)
- Abstract Barrier Barrier
- Frame Position Barrier PositionBarrier
- Body Spherical Barrier BodySphericalBarrier
- Whole-body Self-Collision Avoidance Barrier SelfCollisionBarrier
Example: UR5 manipulator and GO2 quadruped robot with PositionBarrier
Example: YUMI two-armed manipulator with BodySphericalBarrier
Example: G1 humanoid squatting through regulating CoM.
Limit: AccelerationLimit
Task: ComTask for center-of-mass tracking (thanks to @simeon-ned)
Task: LowAccelerationTask for smoother velocities.

Changed

Breaking: remove lm_damping parameter from DampingTask where it wasn't used
CICD: Update ruff to 0.4.3
Configuration accepts list of Control Barrier Functions
DampingTask: Simplify implementation
Update to Pinocchio 3 with 2.7 backward compatibility

Fixed

PostureTask: Match implementation and documentation formula
Fix broken documentation links

Removed

CICD: Disable macOS checks until upstream PyPI package is fixed

- Python
Published by stephane-caron over 1 year ago

pin-pink - v2.1.0

This release adds the RelativeFrameTask developed with @ymontmarin :+1: This new task is a generalization of the frame task that accepts targets with respect to any robot frame. For example:

https://github.com/stephane-caron/pink/assets/1189580/f349bb55-c7f6-4074-a8bf-0b86a5693098

Left: relative frame task (stretch_relative_target.py example)
Right: frame task (stretch_world_target.py example)

This release also brings a few quality-of-use improvements to configurations and costs.

Added

Function get_transform in the Configuration class
Task: relative frame task, where target is w.r.t another robot frame

Changed

Configuration: update function now accepts a configuration vector argument
Costs: setting cost in relative frame task now accepts plain float

- Python
Published by stephane-caron almost 2 years ago

pin-pink - v2.0.0

This release brings a number of fixes and completes the renaming of the BodyTask to FrameTask (details below). It also distributes Pink on conda-forge, which is now the recommended way to install for best performance:

console conda install -c conda-forge pink

Added

Add gain keyword argument to all task constructors where is makes sense
Damping task that minimizes joint velocities
Distribute package on conda-forge
Example on how differential IK may converge to a local constrained optimum
Expose all tasks from the top-level pink module
Handle unbounded joints in custom configuration vectors
Unit test for posture task Jacobian

Changed

Breaking: Define task Jacobian as derivative of the task error
Breaking: Rename BodyNotFound exception to FrameNotFound
Breaking: Rename FrameTask.body to FrameTask.frame

Removed

Body-minus utility function
Spatial-minus utility function

- Python
Published by stephane-caron almost 2 years ago

pin-pink - v1.1.0

This release fixes a bug when handling configuration limits for models that contain unbounded revolute joints.

Changed

Don't check configuration limits when building IK matrices

Fixed

Configuration limits when model has unbounded revolute joints

- Python
Published by stephane-caron about 2 years ago

pin-pink - v1.0.0

This is the first major release of Pink, Python inverse kinematics for articulated robot models, based on Pinocchio. The main update since v0.11.0 is the definition of a proper linear holonomic task on tangent spaces, with accompanying documentation, by @ymontmarin. Thanks! :+1:

API-wise, Levenberg-Marquardt damping is now defined in the base Task class and can therefore be set in any task. This release drops support for Python 3.7, and brings a seasonal batch of new examples and bug fixes.

Added

Example: UR5 arm
Example: flying dual-arm with UR3
General linear holonomic task

Changed

Cost vector is now defined for all tasks
Drop support for Python 3.7
Levenberg-Marquardt damping is now defined for all tasks
Update joint-coupling task to derive from general linear holonomic task

Fixed

Example: Draco 3 numerical stability

- Python
Published by stephane-caron over 2 years ago

pin-pink - v0.11.0

This release upgrades the BodyTask to a FrameTask handling all kinds of frames defined in the robot description. It was contributed by @proyan, thanks! :smiley:

Added

Example: Stretch RE1

Changed

Handle all frames, including non-body frames
Rename BodyTask to FrameTask

- Python
Published by stephane-caron almost 3 years ago

pin-pink - v0.10.0

This release fixes handling of models with/without configuration limits and with/without velocity limits.

Added

Base class Limit for configuration and velocity limits
In-place integration of a velocity from a configuration
Unit tests for configuration limits
Unit tests for velocity limits

Changed

Add pink.limits submodule
Configuration and velocity limits are now stacked rather than pre-reduced
Move configuration limit to ConfigurationLimit class
Move velocity limit to VelocityLimit class

- Python
Published by stephane-caron almost 3 years ago

pin-pink - v0.9.0

This release adds the joint-coupling and linear-holonomic tasks contributed by @shbang91 :+1: The tasks are unit tested and illustrated by a new humanoid example :muscle:

Added

Example: Draco 3 humanoid by @shbang91
Joint-coupling task by @shbang91
Linear holonomic task by @shbang91
Unit tests for joint-coupling and linear holonomic tasks by @shbang91

Changed

Refactor apply_configuration into Configuration constructor
Refactor assume_configuration into Configuration constructor
Refactor task dynamics into compute_error and compute_jacobian

- Python
Published by stephane-caron almost 3 years ago

pin-pink - v0.8.0

This release fixes the Jacobian of the body task, with a dedicated blog post to explain the fix. In short: we were using the frame Jacobian instead of the full task Jacobian (which includes a log-derivative). Using the frame Jacobian works fine in many use cases, but it can also fail drastically in weighted inverse kinematics. Example and details in the blog post :spiral_notepad:

Thanks to @aescande and @Gregwar for their help :+1:

Added

BodyNotFound exception
Document spatial and body minus between transforms
Example: SigmaBan humanoid
Forward keyword arguments of solve_ik to the backend QP solver

Changed

Return type of compute_velocity_limits now includes optionals
VectorSpace type is now immutable

Fixed

Jacobian of the body task

- Python
Published by stephane-caron about 3 years ago

pin-pink - v0.7.0

This revision improves joint limit computations significantly, with fixes, new unit tests and examples on the side.

Added

Bounded subspace of tangent space, that is, restricted to bounded joints
CI: test on both Ubuntu and macOS images
Tangent space from Pinocchio model

Changed

Example: UR3 arm
Expose pink.Task from top-level module
Improve joint limit computations

Fixed

Empty inequalities when model has no bounded joint

- Python
Published by stephane-caron about 3 years ago

pin-pink - v0.6.0

This release makes the solver argument mandatory for all calls to solve_ik.

Note that the project is still in beta, so don't expect proper deprecation paths / API-change preemptive warnings before it hits v1.0.0 :wink:

- Python
Published by stephane-caron about 3 years ago

pin-pink - v0.5.0

With this release, Pink handles more general joint types, including fixed or free flyer root joints, unbounded joints (called continuous in URDF), etc. New examples showcase this on both arms :mechanicalarm: and legged :mechanicalleg: robots.

Banner for Pink v0.5.0

Under the hood, this release also improves on various points of the QP formulation (joint limits, posture task, ...) so that it works nicely with more solvers (e.g. CVXOPT), beyond quadprog and OSQP which were the two main solvers so far.

Added

Body task targets can be read directly from a robot configuration
Example: double pendulum
Example: Kinova Gen2 arm
Example: loading a custom URDF description
Example: visualization in MeshCat
Example: visualization in yourdfpy
Generalize configuration limits to any root joint
Handle descriptions that have no velocity limit
Handle general root joint in configuration limits
Handle general root joint in posture task
Handle unbounded velocity limits in QP formulation
Posture task targets can be read directly from a configuration
Simple rate limiter in pink.utils

Changed

Raise an error when querying a body that doesn't exist
Transition from pink.models to robot_descriptions
Update reference posture in Upkie wheeled biped example
Warn when the backend QP solver is not explicitly selected

Fixed

Unbounded velocities when the backend solver is CVXOPT

- Python
Published by stephane-caron over 3 years ago

pin-pink - v0.4.0

This release brings documentation, full test coverage, and handles robot models installed from PyPI.

Also, it indulges in a project icon :wink:

Added

Coveralls for continuous coverage testing
Document differential inverse kinematics and task targets
Single-task test on task target translations mapped to IK output translations

Changed

Argument to build_from_urdf functions is now the path to the URDF file
Bumped status to beta
Examples use the jvrc_description and upkie_description packages
Use jvrc_description and upkie_description packages from PyPI
Task is now an abstract base class

Fixed

Unit tests for robot models

- Python
Published by stephane-caron over 3 years ago

pin-pink - v0.3.0

This release adds proper handling of joint position and velocity limits.

Added

Joint velocity limits
Configuration limits

Changed

Bumped status to alpha
Configuration limit check now has a tolerance argument

- Python
Published by stephane-caron almost 4 years ago

pin-pink - v0.2.0

This pre-release adds the regularizing posture task and corresponding unit tests.

Added

Check configuration limits against model
Mock configuration type for unit testing
Tangent member of a configuration
Unit test the body task

Changed

Specify path when loading a model description
Switch to the Apache 2.0 license
build_jvrc_model is now build_from_urdf

Fixed

Don't distribute robot models with the library
IK unit test that used robot instead of configuration

- Python
Published by stephane-caron almost 4 years ago

pin-pink - v0.1.0

This is a first working version of the library with a humanoid example that can be run and tweaked. Keep in mind that 0.x versions mean the library is still under active development, with the goal that 1.0 is the first stable version. So, this is still the very beginning :wink:

Added

Body task
Humanoid example

Changed

ConfiguredRobot(model, data) type is now Configuration(model, data, q)

Fixed

Add floating base joint when loading JVRC model

- Python
Published by stephane-caron almost 4 years ago

Recent Releases of pin-pink

pin-pink - v3.4.0

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pin-pink - v3.3.0

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pin-pink - v3.2.0

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pin-pink - v3.1.0

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pin-pink - v3.0.0

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pin-pink - v2.1.0

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pin-pink - v2.0.0

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pin-pink - v1.1.0

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pin-pink - v1.0.0

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pin-pink - v0.11.0

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pin-pink - v0.10.0

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pin-pink - v0.9.0

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pin-pink - v0.8.0

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pin-pink - v0.7.0

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pin-pink - v0.6.0

pin-pink - v0.5.0

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pin-pink - v0.4.0

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pin-pink - v0.3.0

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pin-pink - v0.2.0

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pin-pink - v0.1.0

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