Human Vibration

The OROS Body Vibration tool allow you to evaluate the affect of vibration on the human body according to standards ISO 2651 and ISO 5349. These standard define measurement practice and vibration signal analysis to evaluate the affect on health and and comfort of environmental and equipment vibrations on the Human body.

The ISO 2651 describe the affect on health and comfort of vibration on the whole-body in transportation system, and the ISO 5349 the affect on health of vibration on hands and arms when manipulating machine-tools or vibrating objects. In the following, we will see how to use OROS to evaluate these effect.

This OROS toolkit operate in post analysis mode and will help you to calculate time-weighted signal of acceleration and specific indicators both defined in the standards.

File:OROS BodyVibration Tool.png

Download

Download the program here (version from 04/11/2020) : https://orossas.sharepoint.com/:u:/g/support/EU4wYMKICt1GoI06CuzGsAYBzit5aFCoAt7WC0RoHchAmA?e=dVc7Od

How to use

1. Launch NVGate
   
   
2. Launch OROS_BodyVibration_Tool.exe
   
   
3. Open a project in NVGate
   
File:Open project manager.png

4. In the tool, Click on list measurement to list all the measurement present in the project (only the measurement where the signal files are actually on the disk will be displayed. Ensure you have downloaded signal from the OR3X disk)
   
   
File:Select Meas.png
5. Add the measurement you want to analyse in the "selected list" area (you can select several measurements) using the ">>" button. Use the "<<" button to remove file if needed.
   
   
File:Add Meas.png
6. Select the weighting you want to apply on the time signal
   
   
File:Select filt.png
7. Select the weighting you want to apply for each direction X, Y and Z used for the indicators
   
   
File:Select filt proc.png
8. Select the indicators you want to calculate
   
   
File:Select Indic.png
9. Click on "Start Processing"
   
   
File:Strat Process.png
10. The processing is completed when a the following pop-up window appear. The results ans weighted signal have been generated in the current NVGate project. See the next sections for details.
    
    
File:The end.png

Toolkit results

Time-weighted signal

Studies of the affect of vibrations on the human body suggest that part of the body don't have the same response to vibrations, and will be sensitive to specific frequencies and transient component of vibration signal. In order to represent the sensitivity of the human boy, ISO standards defined time-weighting that must applied to the signal according to the environmental conditions. The following part present you how to apply time-weighting filters to your signal using the toolkit.

Time-weighting filters

As defined in the standards, specific time weighting must be applied to the acceleration signal in order to represent the effect of vibrations on health and comfort. Here is the list of the different time-weighting filters implemented in the toolkit :

Time-weighting filters

$W_{k}$	Time weighting for the Z axis for whole-body measurement (ISO 2651-1)
$W_{d}$	Time weighting for the X and Y axis for whole-body measurement (ISO 2651-1)
$W_{h}$	Time weighting for the hand-arms measurement in any direction (ISO 5349-1)
$W_{f}$	Time weighting for motion sickness measurement in the vertical direction (ISO 2651-1)
$W_{c}$	Time weighting for the X axis for whole-body measurement (ISO 2651-1)
$W_{e}$	Time weighting for all rotational directions for whole-body measurement (ISO 2651-1)
$W_{j}$	Time weighting for the Z axis for head comfort measurement (ISO 2651-1)

Usage in the toolkit

The toolkit allow you to calculate the filtered raw signal with any of the above weighting filters. This will allow you to display spectrums and calculate RMS via post-analysis in NVGate.

To calculate the raw weighted signal, simply select the filters you want in the "Time signal filters" section :

Once the processing in completed, a new measurement containing the filters signal for each selected filter is created in NVGate Project Manager :

File:Filter ProjectManager2.png

You can then load the filtered signal in the player as any signal in NVGate. Each track of the signal is filtered with the corresponding filter.

Health and comfort indicator

In addition to the time-weighting filters, the ISO standards present a series of specific indicators to evaluate the affect of vibrations on the Human body. The following section will present you how to use the toolkit to access these indicators.

Indicators

Time-weighting filters

$RMS$	RMS of the time weighted signal (Calculated from Post processing in NVGate)
$A_{w}$	Daily maximal exposure value (Calculated from Post processing in NVGate)
$MTVV$	Maximum Transient Vibration Value, represent the maximal RMS value of the signal
$VDV$	Vibration Dose Value, taking into account the temporal shocks in the signal
$MSDV$	Motion Sickness Dose Value, representing the comfort in transportation measurement
$D_{k}$	The Acceleration Dose, representing the affect of the vibration on the spine

As defined in the table, $A_{w}$ and RMS indicators can be obtained in NVGate via post-processing of the appropriate weighted signal. The other indicators will be calculated by the toolkit.