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:

• XSens
• xio
• YEI

Compatible with Python 2 and 3.

Dependencies

numpy, scipy, matplotlib, pandas, sympy, easygui

Homepage

http://work.thaslwanter.at/skinematics/html/

Author: Thomas Haslwanter Date: 02-03-2017 Ver: 0.3.8 Licence: BSD 2-Clause License (http://opensource.org/licenses/BSD-2-Clause)

Copyright (c) 2017, 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).

Data-Import

• imyus.import_data ... Read in Rate and stored 3D parameters from a variety of IMUs
• sensors.xio ... Import data recorded with xio-systems
• sensors.xsens ... Import data recorded with XSens-systems
• sensors.yei ... Import data recorded with YEI-systems

MARG Systems

• imus.calc_QPos ... Calculate orientation and position, from angular velocity and linear acceleration
• imus.kalman_quat ... Calculate orientation from IMU-data using an Extended Kalman Filter.

• imus.IMU ... Class for working with data from IMUs

  • imus.IMU.calc_orientation ... calculate orientation
  • imus.IMU.calc_position ... calculate position
  • imus.IMU.setData ... set the properties of an IMU-object

• imus.MadgwickAHRS ... Class for calculating the 3D orientation with the Madgwick-algorithm
• imus.MahonyAHRS ... Class for calculating the 3D orientation with the Mahony-algorithm

Markers

Analysis of signals from video-based marker-recordings of 3D movements

• markers.analyze3Dmarkers ... Kinematic analysis of video-basedrecordings of 3D markers
• markers.movement_from_markers ... 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.quatconj ... Conjugate quaternion
• quat.quatinv ... Quaternion inversion
• quat.quatmult ... Quaternion multiplication

Conversion routines - quaternions

• quat.deg2quat ... Convert number or axis angles to quaternion vectors
• quat.quat2deg ... Convert quaternion to corresponding axis angle
• quat.quat2rotmat ... Convert quaternion to corresponding rotation matrix
• quat.quat2vect ... Extract the vector part from a quaternion
• quat.rotmat2quat ... Convert a rotation matrix to the corresponding quaternion
• quat.vect2quat ... Externd a quaternion vector to a unit quaternion.
• quat.vel2quat ... Calculate orientation from a starting orientation and angular velocity.

Rotation Matrices

Definition of rotation matrices

• rotmat.R1 ... 3D rotation matrix for rotation about the 1-axis
• rotmat.R2 ... 3D rotation matrix for rotation about the 2-axis
• rotmat.R3 ... 3D rotation matrix for rotation about the 3-axis

Conversion Routines - rotation matrices

• rotmat.rotmat2Fick ... Calculation of Fick angles
• rotmat.rotmat2Helmholtz ... Calculation of Helmholtz angles

Symbolic matrices

• rotmat.R1_s() ... symbolix matrix for rotation about the 1-axis
• rotmat.R2_s() ... symbolix matrix for rotation about the 2-axis
• rotmat.R3_s() ... symbolix matrix for rotation about the 3-axis

For example, you can e.g. generate a Fick-matrix, with

>>> R_Fick = R3_s() * R2_s() * R1_s()

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.qrotate ... Quaternion indicating the shortest rotation from one vector into another.
• vector.rotate_vector ... Rotation of a vector

Interactive Data Analysis

• viewer.ts ... interactive viewer for time series data