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Table of Contents
FP Type 1
A Type 1 force platform is an explicit representation of the force vector that directly specifies the Force, Centre of Pressure, and Free Moment signals in the force platform's coordinate system.
Channels
A Type 1 force platform records 6 ANALOG channels containing the following information:
[Original Analog]= [Fx, Fy, Fz, COPx, COPy, Tz]
Calculating the Force Signals
Calculating the desired force signals in the force platform's coordinate system consists of the following steps:
- Compute baselines by averaging the analog signals for the specified FP_ZERO frames
- Subtract each channel's baseline from its recorded signal
- Calculate the force signals of interest
- Transform the signals into the Laboratory Coordinate System
Force Vector
The Force vector for a Type 1 force platform is calculated as follows:
Force[X]= Fx Force[Y]= Fy Force[Z]= Fz
Centre of Pressure
The COFP signal for a Type 1 force platform is calculated as follows:
COP[X]= Mx*LengthConversion COP[Y]= My*LengthConversion COP[Z]= ORIGIN[Z]*LengthConversion
Where
LengthConversion = Point units conversion to meters
for example, if the POINT units are millimetres then the LengthConversion term is 0.001.
Free Moment
The Free Moment signal for a Type 1 force platform is calculated as follows:
FreeMoment[X]= 0 FreeMoment[Y]= 0 FreeMoment[Z]= Tz
Transforming Signals into the Laboratory Coordinate System
The transformation is defined by the location of the force platform corners, and is common to all force platforms.