DOI: 10.35097/uwz0qdyzh8h8uekw
title: Measurements of the Mechanical Impedance and Vibration Power Absorption for Varying Grip and Push Forces

description: The data set contains the raw as well as the evaluated data from a subject study with 6 subjects to measure the mechanical impedance and the vibration power absorbtion while varying the grip and push forces in ten levels between 10-135N and 10-110N respectively. The measuring handle on which the study was conducted complies with the specifications in ISO10068:2012. The subjects were randomised to hold the force levels while vibrations were applied translatory along the lower arm axis (zh-axis according to DIN5349:2001) to their hand-arm system via a shaker system, with the posture of the subjects lying within the ranges specified in ISO 10819:2022. The excitation was a multisine with frequencies between 10 to 500 Hz in 5 Hz steps with an root mean square value of 40m/s². The acquisition time of each measurement is 16.5 sec, for the evaluation the data is cutted to exclude the first 4 sec and the last 1.5 sec.
description: The data set consists of five types. 
1) In table AnthroDemoMaxForcesTable.mat the anthropometric data, the gender and the maximum grip and push forces of the subjects are listed. 
2) In Matrix resultsMatrix.mat the mechanical impedance and the phase angle of the measurements of the subjects study are summarized. The resulting mechanical impedance and the phase angle are already calibrated in each direction, and can be used directly from the matrix. The matrix consists of three dimensions, the first is the mechanical impedance and the phase angle in the direction of excitation (zh), the second dimension is the cross-axial mechanical impedance and the phase angle in xh-direction, and the third dimension is the cross-axial mechanical impedance and the phase angle in yh-direction. The directions are named according to the coordinate system of DIN 5349:2001. Each row of the matrix represents one measurement. The following data information and results are in the corresponding columns:
- 1: number of the subect
- 2: is 0 if the grip and push forces during the measurements are within the range of 5N and 14%, otherwise a 1 is at this position. This can be used for data exclusion. 
- 3: predefined push force value
- 4: predefined grip force value
- 5: experiment number according to the resultsMatrix for each subject
- 6: sequence of the taken measurements of each subject, due to a randomized test plan
- 7: mean measured grip force
- 8: median measured grip force
- 9: standard deviation of the measured grip force
- 10: mean measured push force
- 11: median measured push force
- 12: standard deviation of the measured push force
- 13: mechanical impedance at 10 Hz
- 14: phase angle at 10 Hz
- 15: mechanical impedance at 15 Hz
- 16: phase angle at 15 Hz
- 13:2:209 mechanical impedance between 10-500 Hz in 5 Hz steps
- 14:2:210 phase angle of the mechanical impedance between 10-500 Hz in 5 Hz steps
3) The VPAmatrix.mat is according to resultsMatrix.mat, instead of the mechanical impedance in positions 13:2:209 the vibration power absorption values are listed and in positions 14:2:210 the weighted vibration power absorption according to ISO10068:2012 is listed. Here, only the direction of excitation is evaluated. 
4) Raw data, the data name consists of the time stamp and is named afterwards in the same order as the matrix: Px, where x is the number of the subject, followed by the push and then the grip force and the position in the matrix. In each struct the metadata, the time and the signals are saved. The excitation in the subject study was applied along the forearm axis (zh according to DIN5349:2001). Therefore, the signals az_top and az_bottom are the acceleration at the top and bottom of the measuring handle in excitation direction. The signals Fz_top and Fz_bottom are the forces in the direction of excitation, both are used to calculate the mechanical impedance and vibration power absorption in the excitation direction (dimension 1 in the resultsMatrix.mat file). The signals used for the second dimension of the resultsMatrix are Fx_top, Fx_bottom, az_top, az_bottom, for the third dimension Fy_top, Fy_bottom, az_top, az_bottom are used.
5) emptyMeasurement.mat is a measurement of the unloaded handle while excited with the same signal as in the subject study. This file can be used for the calibration of the handle.