Description:

The coordinate system is right hand rule. X cross Y gives Z and Roll is right hand rule about X, Pitch is right hand rule about Y, and Yaw is right hand rule about Z.

Vector Storage:

All linear three vectors (LinPos, LinVel) store their values as [X, Y, Z]. All angular three vectors (AngVel) store their values as [Roll, Pitch, Yaw]. The transformation matrix TM is stored:

Pre-multiplying a local vector by the TM will generate the vector in global coordinates.

Multibody Dynamics, Link Numbers and 60 and 20 Length Vectors:

Please refer to Multibody Dynamics and 60 Length Vectors for information on 60
length vectors.

Methodology:

The Offset is specified in the local coordinates of the current body. This is converted to global
coordinates as Goffset.

The offset component takes the input position, velocity, and acceleration from Side 3 and calculates the position, velocity and acceleration at the point offset by the value of GOffset.

The offset also takes the internal force from Side 1 and outputs this on Side 3. It takes the moment from Side 1 adds in the moment due to the cross product of the internal force of the Offset and outputs this on Side 3. Essentially:

Moment3 = Moment1 + GOffset X Force1
Force3 = Force1
 

SimRealVar Force1[60] - Global Force (N)
SimRealVar Moment1[60] - Global Moment (Nm)

Outputs:

SimRealVar LinAccel1[60] - Global Linear Acceleration (m/s/s)
SimRealVar LinVel1[3] - Global Linear Velocity (m/s)
SimRealVar LinPos1[3] - Global Linear Position (m)
SimRealVar AngAccel1[60] - Global Angular Acceleration (rad/s/s)
SimRealVar AngVel1[3] - Global Angular Velocity (rad/s)
SimRealVar TM1[9] - Transformation Matrix (ND)
SimRealVar LinkNumber1[20] - Link Number Output (ND)
 

SimRealVar Offset[3] - Offset in Local Coordinates (m)
 

SimRealVar LinAccel3[60] - Global Linear Acceleration (m/s/s)
SimRealVar LinVel3[3] - Global Linear Velocity (m/s)
SimRealVar LinPos3[3] - Global Linear Position (m)
SimRealVar AngAccel3[60] - Global Angular Acceleration (rad/s/s)
SimRealVar AngVel3[3] - Global Angular Velocity (rad/s)
SimRealVar TM3[9] - Transformation Matrix (ND)
SimRealVar LinkNumber3[20] - Link Number Input (ND)

Outputs:

SimRealVar Force3[60] - Global Force (N)
SimRealVar Moment3[60] - Global Moment (Nm)
 

return to component list