Path: SCPro/DynamicalModels
% Spacecraft orbit dynamics with time-varying mass.
This is a point mass with an external force input.
The position is in km. The gravity model is for a point mass.
The force are constant across the integration time step.
The body has time varying mass.
In this function d.mass is the dry mass. The fuel mass is in the state
vector x. If m is less than zero mDot is set to zero.
The function fDist (which should be a handle) is of the form
force = MyFun( x, t, d )
You can add additional fields to d. force must be in N in the body
frame and torque in Nm in the body frame. This function allows you
to add forces and torques within the integration loop. This is
required for forces and torques that are functions of time or the
state vector.
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Form:
d = RHSPointMass;
xDot = RHSPointMass( x, t, d )
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Inputs
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x (7,1) State vector [r;v;m] (km, km/s, kg)
t (1,1) Time (unused) (s)
d (1,1) Data structure for the simulation
.force (3,1) External force (N)
.mass (1,1) Vehicle dry mass (kg)
.mu (1,1) Gravitational parameter (km^3/s^2)
.fDist (1,:) Disturbance function handle
.mDot (1,1) Mass rate (kg/s)
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Outputs
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xDot (14,1) d[r;v;;m]/dt
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Common: Database/Constant Math: Linear/Mag
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