## MBModel:

Path: SC/Dynamics

```% Momentum bias spacecraft model
Computes the state space description of a momentum bias spacecraft where the
internal momentum is fixed. If dT is not input it returns the continuous time
plant. If dT is input it returns the discrete time plant. In either case, the
plant is linearized about wo. The state vector is

[thetax;thetay;thetaz;omegax;omegay;omegaz]

Where the state vector is with respect to the rotating frame
defined by wo.

The outputs are the angles, i.e. the first three elements in the
state vector.

If h and wo are not in the same direction or inr is not diagonal,
dxdt will be nonzero and you will get constant disturbance torques.

If only one output is specified it gives the right hand side
of the nonlinear dynamical equations of motion. You need to use
the kinematics routines to get the nonlinear kinematics equations.

--------------------------------------------------------------------------
Form:
[a,b,c,d,dxdt] = MBModel(inr,h,wo)
[a,b,c,d,dxdt] = MBModel(inr,h,wo,dT)
[wDot]         = MBModel(inr,h,w,torque)
--------------------------------------------------------------------------

------
Inputs
------
inr           (3,3)  Inertia matrix
h             (3,1)  Internal momentum vector
wo            (3,1)  Orbit rate vector
dT            (*,1)  Sampling period (1) or torque vector (3)

-------
Outputs
-------
a             (6,6)  Plant matrix
b             (6,3)  Input matrix
c             (3,6)  Output matrix
d             (3,3)  Feedthrough matrix

or

wDot          (3,1)  State derivative

--------------------------------------------------------------------------
```

## Children:

```Common: Control/C2DZOH
Math: Linear/SkewSymm
```

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