beautypg.com

Discussed above – PNI SENtral MandM User Manual

Page 31

background image

PNI Sensor Corporation

Doc #1020129 revE

SENtral M&M Technical Datasheet

Page 30

Rotation Vector

The rotation vector is the first three elements of the quaternion output, Qx, Qy, and Qz. The

fourth element, Qw, is not included in the rotation vector. The rotation vector in ENU

convention will be the first three elements of Q

ENU

, discussed above.

Rotation Matrix, or Direction Cosine Matrix (DCM)

The rotation matrix, also known as the direction cosine matrix (DCM), can be established

from the quaternion output using the following conversion. Q

ENU

values can be substituted

to give the rotation matrix with an ENU convention.

Qw

2

+ Qx

2

– Qy

2

– Qz

2

2*(Qx*Qy + Qw*Qz)

2*(Qx*Qz

– Qw*Qy)

R =

2*(Qx*Qy

– Qw*Qz)

Qw

2

– Qx

2

+ Qy

2

– Qz

2

2*(Qy*Qz + Qw*Qy)

2*(Qx*Qz + Qw*Qy)

2*(Qy*Qz

– Qw*Qy)

Qw

2

– Qx

2

– Qy

2

+ Qz

2