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/

Installation

You can install scikit-kinematics with

pip install scikit-kinematics

and upgrade to a new version with

pip install --upgrade --no-deps scikit-kinematics

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.IMU.set\_qtype ... sets q\_type, and automatically
        performs the relevant calculations.

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
view.orientation ... visualize and animate orientations, expressed as quaternions.

Errata

The file Errata.pdf contains the a list of mistakes in the manuscript, and the corresponding corrections.

gizemozd / scikit-kinematics