Second derivative of function rotation_dq(theta) with respect to time.
function der2_rotation_dq extends Modelica.Icons.Function; input SI.Angle theta; input SI.AngularFrequency omega "d/dt theta"; input SI.AngularAcceleration omega_dot "d/dt omega"; output Real[2, 2] der2_R_dq "d/2dt2 rotation_dq"; end der2_rotation_dq;