Path: Interplanetary/Landers
% Implements a bilinear tangent landing controller.
This is for a circular planet. It uses LandingControl.m
The function has two paths. One is used on initialization, the other
each time step to update the controller. The function will plot
the beta angles for the controller.
You can bypass attitude control in which case the thrust will always
be in the correct direction.
Terminal descent happens after the bilinear tangent runs out of steps
or if the spacecraft is below a landing altitude threshold.
All data and inputs and outputs are stored in the data structure, d.
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Form:
d = LandingControlBilinear( action, d )
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Inputs
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action (1,:) 'initialize' or 'update'
d (.) Data structure inputs
.nG (1,1) Engine acceleration is this number times
gravity
.mu (1,1) Gravitational constant
.inertia (1,1) Inertia matrix
.aCS (.) PID3Axis data structure
.zeta (1,1) Damping ratio
.omega (1,1) Undamped natural frequency
.tauInt (1,1) Integrator time
.omegaR (1,1) Rate filter frequency
.mass (1,1) Mass (kg)
.bypassACS (1,1) 1 = bypass attitude control
.landing (.) Landing control data structure
.omega (1,1) Undamped natural frequency
.zeta (1,1) Damping ratio
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Outputs
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d (1,1) Data structure outputs
.aCS (.) PID3Axis data structure
.eci_vector (3,1) Pointing vector
.a (1,1) Acceleration
.thrust (1,1) Engine thrust
.beta (1,:) Thrust direction angles
.t (1,:) Corresponding times
.throttle (1,1) Throttle setting
.index (1,1) Index for betas
.landing (.) Landing control data structure
.gainForward (1,1) Forward gain
.tau (1,1) Time constant
.accel (1,1) Acceleration
.g (1,1) Gravity
.mode (1,1) Mode
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See also LandingControl, BilinearTangentLaw, PIDMIMO, PID3Axis
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Interplanetary: Landers/BilinearTangentLaw Interplanetary: Landers/LandingControl SCPro: ProControl/PID3Axis Common: Control/PIDMIMO Common: Database/Constant Common: Graphics/Plot2D Common: Graphics/TimeLabl Common: MassProperties/Inertias Common: Quaternion/QTForm Math: Linear/Cross Math: Linear/Dot Math: Linear/Mag Math: Linear/Unit
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