Path: SC/Dynamics
% Computes the right hand side for a spacecraft with reaction wheels.
The wheels can have damping and Coulomb friction and stiction.
If you call it without any arguments it will return the default data
structure.
The gravity model is a point mass planet. The inertia of the body
does not include the RWA polar inertia.
RWA stands for reaction wheel assembly.
The default data structure is for 3 orthogonal reaction wheels but the
model allows for any number of wheels. Uses ReactionWheelFriction.m
No demo.
--------------------------------------------------------------------------
Form:
d = RHSRWAOrbit; % To get the data structure
[xDot, hECI] = RHSRWAOrbit(x,~,d)
--------------------------------------------------------------------------
------
Inputs
------
x (13+n,1) State vector [r;v;q;omega;omegaRWA]
t (1,1) Time (unused)
d (.) Data structure
.inr (3,3) Body inertia matrix
.mass (1,1) Spacecraft mass
.mu (1,1) Gravitational constant
.force (3,1) External force in the ECI frame (kN)
.torque (3,1) External torque in the body frame
.inrRWA (n,1) Polar inertia of each wheel
.torqueRWA (n,1) Torques on each wheel
.uRWA (3,n) Unit vectors for the RWA
.friction (.) Friction data structure
-------
Outputs
-------
xDot (13+n,1) State vector derivative d[r;v;q;omega;omegaRWA]/dt
hECI (3,1) Inertial angular momentum
--------------------------------------------------------------------------
SC: Dynamics/RHSReactionWheel Math: Linear/Mag
Back to the SC Module page