rigid-body-motion 0.9.1

Python utilities for estimating and transforming rigid body motion.

rigid-body-motion

Python utilities for estimating and transforming rigid body motion.

Documentation: https://rigid-body-motion.readthedocs.io

Overview

This package provides a high-level interface for transforming arrays describing motion of rigid bodies between different coordinate systems and reference frames. The core of the reference frame handling is a fast re-implementation of ROS’s tf2 library using numpy and numpy-quaternion. The package also provides first-class support for xarray data types.

Installation

rigid-body-motion can be installed via pip:

$ pip install rigid-body-motion

or via conda:

$ conda install -c phausamann -c conda-forge rigid-body-motion

Highlights

rigid-body-motion makes it possible to:

• Construct trees of static and moving reference frames

• Lookup transforms and velocities across the tree

• Seamlessly transform positions, orientations and velocities across the tree

• Estimate transforms from motion data

• Transform data into different coordinate representations

• Import data from common motion tracking systems

• Visualize reference frames and motion data with matplotlib or RViz

• … and more!

Credits

This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.

History

0.9.1 (January 13th, 2022)

Bug fixes & improvements

• Fixed package installation through pip (version 0.9.0 is no longer available).

0.9.0 (December 29th, 2021)

Breaking changes

• Dropped support for Python 3.6.

Bug fixes & improvements

• Fixed issue with matplotlib versions >= 3.5.

0.8.0 (May 27th, 2021)

New features

• New ros.init_node method to initialize a ROS node and optionally start a ROS master.

Bug fixes & improvements

• All ROS dependencies are now lazily imported.

0.7.0 (May 19th, 2021)

New features

• New from_euler_angles utility method.

Bug fixes & improvements

• Importing ROS interface classes will not fail silently anymore and instead show the traceback of the import error.

0.6.0 (May 17th, 2021)

Breaking changes

• Example data is now fetched via the pooch library and no longer a part of the package itself.

New features

• New io module for import/export methods.

• New ros.RosbagWriter class for writing rosbag files.

0.5.0 (March 16th, 2021)

Breaking changes

• Top-level reference frame transform and lookup methods now all accept a return_timestamps argument that is False by default. Previously, methods would return timestamps only if the result of the transformation was timestamped. This does not affect the xarray interface.

• lookup_transform now returns the correct transformation from the base frame to the target frame (instead of the other way around).

• ReferenceFrame.get_transformation is deprecated and replaced by ReferenceFrame.lookup_transform.

New features

• New plot module with plotting methods for static reference frames and arrays of points, quaternions and vectors.

• New lookup_pose method that calculates the pose of a frame wrt another.

Bug fixes & improvements

• Fixed "reference_frame" attribute incorrectly set by transform_vectors.

0.4.1 (February 18th, 2021)

Bug fixes & improvements

• Fixed transform_coordinates failing when spatial dimension is first axis of array.

• Fixed transform_linear_velocity and transform_angular_velocity failing when reference frame or moving frame is transformed across only static transforms.

• Added allow_static parameter to lookup_twist, lookup_angular_velocity and lookup_linear_velocity to return zero velocity and no timestamps across only static transforms.

0.4.0 (February 11th, 2021)

New features

• New lookup_linear_velocity and lookup_angular_velocity top-level methods.

• New render_tree top-level method for printing out a graphical representation of a reference frame tree.

• lookup_twist now accepts a mode parameter to specify the mode for angular velocity calculation.

Bug fixes & improvements

• Fixed a bug where estimated angular velocity was all NaN when orientation contained NaNs.

0.3.0 (December 8th, 2020)

New features

• Reference frames with timestamps now accept the discrete parameter, allowing for transformations to be fixed from their timestamp into the future.

• rbm accessor for DataArrays implementing qinterp and qinv methods.

• New best_fit_rotation and qinterp top-level methods.

Bug fixes & improvements

• Refactor of internal timestamp matching mechanism defining a clear priority for target timestamps. This can result in slight changes of timestamps and arrays returned by transformations but will generally produce more accurate results.

• Added mode and outlier_thresh arguments to estimate_angular_velocity.

• Fixed issues with iterative_closest_point.

0.2.0 (October 22nd, 2020)

New features

• New estimate_linear_velocity and estimate_angular_velocity top-level methods.

• New qmul top-level method for multiplying quaternions.

0.1.2 (October 7th, 2020)

Improvements

• Use SQUAD instead of linear interpolation for quaternions.

0.1.1 (September 17th, 2020)

Bug fixes

• Fix transformations failing for DataArrays with non-numeric coords.

0.1.0 (September 17th, 2020)

• First release