rk4 Class Reference

Public Member Functions
array< float, 2 >	accel (array< float, 2 > u, float rho)
	A function that calculates the acceleration of the rocket at a given altitude and velocity given by the rk4 simulation. More...
array< float, 2 >	rk4_step (array< float, 2 > state, float dt, float rho)
	A function that propagates the rk4 apogee simulation by one time step. More...
array< float, 2 >	sim_apogee (array< float, 2 > state, float dt)
	A function that returns the simulated apogee of the rocket from state estimates. More...
float	cd (float alt, float vel)
	A function that returns the Coefficient of drag at a given altitude and velocity (based on mach number) More...

Public Attributes
array< double, 151 >	poly

Member Function Documentation

accel()

array< float, 2 > rk4::accel	(	array< float, 2 >	u,
		float	rho
	)

A function that calculates the acceleration of the rocket at a given altitude and velocity given by the rk4 simulation.

Parameters

u	an array containing the altitude and vertical velocity from the rk4 apogee simulation
rho	the air density returned from the atmosphere class

Returns

array<float, 2> the velocity and acceleration (fixed frame) due to aerodynamic forces at the current step of the rk4

cd()

float rk4::cd	(	float	alt,
		float	vel
	)

A function that returns the Coefficient of drag at a given altitude and velocity (based on mach number)

Parameters

alt	the current altitude from the kalman filter
vel	the current velocity from the kalman filter

Returns

float the Coefficient of drag at the present estimated state

rk4_step()

array< float, 2 > rk4::rk4_step	(	array< float, 2 >	state,
		float	dt,
		float	rho
	)

A function that propagates the rk4 apogee simulation by one time step.

Parameters

state	the rk4 altitude and velocity
dt	the time step size
rho	the density of the air at a given rk4 step altitude

Returns

array<float, 2> the next rk4 state

sim_apogee()

array< float, 2 > rk4::sim_apogee	(	array< float, 2 >	state,
		float	dt
	)

A function that returns the simulated apogee of the rocket from state estimates.

Parameters

state	altitude and velocity from kalman filter
dt	the time step size

Returns

array<float, 2> the predicted apogee and velocity at that altitude (should be close to zero)

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The documentation for this class was generated from the following files:

• flight/mcu/lib/teensyShared/rk4.h
• flight/mcu/lib/teensyShared/rk4.cpp