2021-11-09 16:05:25 +01:00

70 lines
2.4 KiB
C++

/****************************************************************************
*
* Copyright (c) 2021 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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****************************************************************************/
#pragma once
#include <lib/mathlib/math/filter/AlphaFilter.hpp>
class MovingDiff
{
public:
float update(float value, float dt_s)
{
if (!PX4_ISFINITE(value) || (dt_s < FLT_EPSILON)) {
// Ignore NAN
return NAN;
}
_difference_filter.setParameters(dt_s, .1f);
// Leave _diff at 0.0f if we don't have a _last_value yet.
if (PX4_ISFINITE(_last_value)) {
const float new_diff = (value - _last_value) / dt_s;
_difference_filter.update(new_diff);
}
_last_value = value;
return _difference_filter.getState();
}
void reset()
{
_difference_filter.reset(0.f);
_last_value = NAN;
}
private:
AlphaFilter<float> _difference_filter;
float _last_value{NAN};
};