scikit-kinematics
scikit-kinematics primarily contains functions for working with 3D kinematics, e.g quaternions and rotation matrices. This includes utilities to read in data from the following IMU-sensors:
- polulu
- XSens
- xio
- xio-NGIMU
- YEI
Compatible with Python >= 3.5
Dependencies
numpy, scipy, matplotlib, pandas, sympy, easygui
Homepage
http://work.thaslwanter.at/skinematics/html/
Author: Thomas Haslwanter Date: 08-05-2018 Ver: 0.7.7 Licence: BSD 2-Clause License (http://opensource.org/licenses/BSD-2-Clause)
Copyright (c) 2018, Thomas Haslwanter All rights reserved.
Installation
You can install scikit-kinematics with
pip install scikit-kinematics
and upgrade to a new version with
pip install scikit-kinematics -U
IMUs
Analysis of signals from IMUs (intertial-measurement-units). Read in data, calculate orientation (with one of the algorithms below)
- get_data ... This method must be taken from one of the existing sensors, or from your own sensor. Currenlty the following sensors types are available: * XSens * xio (original, and NGIMU) * yei * polulu
- calc_position
MARG Systems
- imus.analytical ... Calculate orientation and position, from angular velocity and linear acceleration
- imus.kalman ... Calculate orientation from IMU-data using an Extended Kalman Filter.
- imus.IMU ... Class for working with data from IMUs
- imus.IMU.calc_position ... calculate position
- imus.IMU.setData ... set the properties of an IMU-object
- imus.Madgwick ... Class for calculating the 3D orientation with the Madgwick-algorithm
- imus.Mahony ... Class for calculating the 3D orientation with the Mahony-algorithm
Markers
Analysis of signals from video-based marker-recordings of 3D movements
- markers.analyze_3Dmarkers ... Kinematic analysis of video-basedrecordings of 3D markers
- markers.find_trajectory ... Calculation of joint-movements from 3D marker positions
Quaternions
Note that all these functions work with single quaternions and quaternion vectors, as well as with arrays containing these.
Quaternion class
- quat.Quaternion ... class, including overloading for multiplication and
- division (e.g. "quatCombined = quat1 * quat2"), import and export
Functions for working with quaternions
- quat.q_conj ... Conjugate quaternion
- quat.q_inv ... Quaternion inversion
- quat.q_mult ... Quaternion multiplication
- quat.q_scalar ... Extract the scalar part from a quaternion
- quat.q_vector ... Extract the vector part from a quaternion
- quat.unit_q ... Extend a quaternion vector to a unit quaternion.
Conversion routines - quaternions
- quat.calc_angvel ... Calculates the velocity in space from quaternions
- quat.calc_quat ... Calculate orientation from a starting orientation and angular velocity.
- quat.convert ... Convert quaternion to corresponding rotation matrix or Gibbs vector
- quat.deg2quat ... Convert number or axis angles to quaternion vectors
- quat.quat2seq ... Convert quaternions to sequention rotations ("nautical" angles, etc)
- quat.scale2deg ... Convert quaternion to corresponding axis angle
Rotation Matrices
Definition of rotation matrices
- rotmat.R ... 3D rotation matrix for rotation about a coordinate axis
Conversion Routines - rotation matrices
- rotmat.convert ... Convert a rotation matrix to the corresponding quaternion
- rotmat.seq2quat ... Convert nautical angles etc. to quaternions
- rotmat.sequence ... Calculation of Euler, Fick, Helmholtz, ... angles
Symbolic matrices
- rotmat.R_s() ... symbolix matrix for rotation about a coordinate axis
For example, you can e.g. generate a Fick-matrix, with
>>> R_Fick = R_s(2, 'theta') * R_s(1, 'phi') * R_s(0, 'psi')
Spatial Transformation Matrices
- rotmat.stm ... spatial transformation matrix, for combined rotations/translations
- rotmat.stm_s() ... symbolix spatial transformation matrix
Denavit-Hartenberg Transformations
- rotmat.dh ... Denavit-Hartenberg transformation matrix
- rotmat.dh_s ... symbolic Denavit-Hartenberg transformation matrix
Vectors
Routines for working with vectors These routines can be used with vectors, as well as with matrices containing a vector in each row.
- vector.normalize ... Vector normalization
- vector.project ... Projection of one vector onto another one
- vector.GramSchmidt ... Gram-Schmidt orthogonalization of three points
- vector.q_shortest_rotation ... Quaternion indicating the shortest rotation from one vector into another.
- vector.rotate_vector ... Rotation of a vector
- vector.target2orient ... Convert target location into orientation angles
Interactive Data Analysis
- viewer.ts ... interactive viewer for time series data