WM
The WM function returns the magnitude of the angular velocity vector (in radians per units of time) of marker i with respect to marker j. Marker j defaults to the global coordinate system if it is not specified.
Note: | The values returned by the functions have the same units defined in the UNITS statement except for angular values. All angular values are returned in radians, all angular velocities are returned in radians per units of time (as defined in the UNITS statement), all angular accelerations are returned in radians per units of time squared. Functions RTOD and DTOR may be helpful to create angular expressions involving degrees and radians. For example, the below statements create a constraint to keep the angular velocity WX(8, 9) equal to 2.5 degrees per second. UNITS/SYSTEM = MKS ! Using seconds GCON/1, FUNCTION = WX(8, 9) – 2.5*DTOR ! Convert degrees to radians |
Format
WM(i[,j])
Arguments
i | The marker whose velocity is being measured. |
j | The marker with respect to which the velocity is being measured. Set j = 0, while still specifying i, if you want j to default to the global coordinate system. |
Extended Definition
Mathematically, WM is calculated as follows:
where:
■
is the angular velocity vector of marker i in ground.
is the angular velocity vector of marker i in ground.■
is the angular velocity vector of marker j in ground.
is the angular velocity vector of marker j in ground.Examples
MARKER/1236, QP=4,6,7 EU=90D,90D,90D, PART=23
MARKER/2169, PART=16
REQUEST/16
,F1=WM(1236,2169)/
,F2=WX(1236,2169,2169)/
,F3=WY(1236,2169,2169)/
,F4=WZ(1236,2169,2169)
MARKER/2169, PART=16
REQUEST/16
,F1=WM(1236,2169)/
,F2=WX(1236,2169,2169)/
,F3=WY(1236,2169,2169)/
,F4=WZ(1236,2169,2169)
In its first column, REQUEST/16 contains the magnitude of the angular velocity vector of Marker 1236 and Marker 2169.
See other Velocity measures available.