low_pass_zoh_filter.h File Reference

A first order low pass filter using Zero Order Hold (ZOH) discretization. More...

#include "std.h"
#include "math/pprz_algebra_int.h"

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Data Structures
struct	FirstOrderZOHLowPass
	Zero Order Hold (ZOH) discrete first order low pass filter structure. More...

Functions
static void	init_first_order_zoh_low_pass (struct FirstOrderZOHLowPass *filter, const float tau, const float sample_time, float value)
	Init first order ZOH low pass filter.
static float	update_first_order_zoh_low_pass (struct FirstOrderZOHLowPass *filter, const float value)
	Update first order ZOH low pass filter state with a new value.
static float	reset_first_order_zoh_low_pass (struct FirstOrderZOHLowPass *filter, const float value)
	Reset the first order ZOH low-pass filter to a specific value.
static float	get_first_order_zoh_low_pass (const struct FirstOrderZOHLowPass *filter)
	Get current value of the first order ZOH low pass filter.
static void	update_first_order_zoh_low_pass_tau (struct FirstOrderZOHLowPass *filter, const float tau, const float sample_time)
	Update time constant (tau parameter) for first order ZOH low pass filter.

Detailed Description

A first order low pass filter using Zero Order Hold (ZOH) discretization.

Definitions and inline functions for 1st order low-pass ZOH filter vector types.

Provides structures and functions to initialize, update, reset, and get outputs from 1st order low-pass ZOH filter vectors.

Author

Justin Dubois j.p.g.nosp@m..dub.nosp@m.ois@s.nosp@m.tude.nosp@m.nt.tu.nosp@m.delf.nosp@m.t.nl

Definition in file low_pass_zoh_filter.h.

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Data Structure Documentation

FirstOrderZOHLowPass

struct FirstOrderZOHLowPass

Zero Order Hold (ZOH) discrete first order low pass filter structure.

This structure represents a first order low pass filter implemented using the Zero Order Hold (ZOH) method for discretization. It maintains the necessary state for filtering operations.

Definition at line 38 of file low_pass_zoh_filter.h.

Data Fields
float	discrete_time_constant
float	last_in
float	last_out

Function Documentation

get_first_order_zoh_low_pass()

static float get_first_order_zoh_low_pass ( const struct FirstOrderZOHLowPass *  filter )

inlinestatic

Get current value of the first order ZOH low pass filter.

Parameters

[in]

filter

first order ZOH low pass filter structure

Returns

current value of the filter

Definition at line 100 of file low_pass_zoh_filter.h.

References FirstOrderZOHLowPass::last_out.

init_first_order_zoh_low_pass()

static void init_first_order_zoh_low_pass ( struct FirstOrderZOHLowPass *  filter, const float  tau, const float  sample_time, float  value  )

inlinestatic

Init first order ZOH low pass filter.

The ZOH discretization method is used to convert a continuous-time first order low pass filter into its discrete-time equivalent which matches the continuous-time behavior at the sampling instants exactly when holding the input constant between samples.

Parameters

[out]	filter	first order ZOH low pass filter structure
[in]	tau	time constant of the first order low pass filter [s]
[in]	sample_time	sampling period of the signal [s]
[in]	value	initial value of the filter

Definition at line 56 of file low_pass_zoh_filter.h.

References FirstOrderZOHLowPass::discrete_time_constant, foo, FirstOrderZOHLowPass::last_in, and FirstOrderZOHLowPass::last_out.

Referenced by init_first_order_zoh_low_pass_array().

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reset_first_order_zoh_low_pass()

static float reset_first_order_zoh_low_pass ( struct FirstOrderZOHLowPass *  filter, const float  value  )

inlinestatic

Reset the first order ZOH low-pass filter to a specific value.

Parameters

[in,out]	filter	first order ZOH low pass filter structure
[in]	value	Value to reset the filter to

Returns

The reset value

Definition at line 87 of file low_pass_zoh_filter.h.

References FirstOrderZOHLowPass::last_in, and FirstOrderZOHLowPass::last_out.

update_first_order_zoh_low_pass()

static float update_first_order_zoh_low_pass ( struct FirstOrderZOHLowPass *  filter, const float  value  )

inlinestatic

Update first order ZOH low pass filter state with a new value.

Parameters

[in,out]	filter	first order ZOH low pass filter structure
[in]	value	new input value of the filter

Returns

new filtered value

Definition at line 72 of file low_pass_zoh_filter.h.

References FirstOrderZOHLowPass::discrete_time_constant, FirstOrderZOHLowPass::last_in, and FirstOrderZOHLowPass::last_out.

Referenced by update_first_order_zoh_low_pass_array().

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update_first_order_zoh_low_pass_tau()

static void update_first_order_zoh_low_pass_tau ( struct FirstOrderZOHLowPass *  filter, const float  tau, const float  sample_time  )

inlinestatic

Update time constant (tau parameter) for first order ZOH low pass filter.

Parameters

[in,out]	filter	first order ZOH low pass filter structure
[in]	tau	time constant of the first order low pass filter [s]
[in]	sample_time	sampling period of the signal [s]

Definition at line 110 of file low_pass_zoh_filter.h.

References FirstOrderZOHLowPass::discrete_time_constant, and foo.