satcat5::ptp::CoeffPI Struct Reference

Detailed Description

Loop-filter coefficients for use with the "ControllerPI" class.

All floating-point calculations can be run at build-time.

The process requires three arguments:

• "tau_secs" is the desired filter time constant in seconds. A time constant of about 5.0 seconds is typical.
• "damping" is the unitless damping ratio, zeta. Default 0.707 is slightly underdamped for reduced settling time.

See also: Stephens & Thomas, "Controlled-root formulation for digital phase-locked loops", IEEE Transactions on Aerospace and Electronic Systems 1995, doi: 10.1109/7.366295. https://ieeexplore.ieee.org/abstract/document/366295

Definition at line 224 of file ptp_filters.h.

#include <ptp_filters.h>

Public Member Functions
constexpr	CoeffPI (double tau_secs)
	Calculate tracking-loop coefficients.
	CoeffPI (const CoeffPI &t)=default
CoeffPI &	operator= (const CoeffPI &t)=default
bool	ok () const
	Are all coefficients large enough to mitigate rounding error?

Static Public Attributes
static constexpr unsigned	SCALE = 60
	Fixed-point scaling of each coefficient by 2^-N. More...

Static Protected Member Functions
static constexpr double	alpha (double zeta)
static constexpr double	k1 (double tau, double zeta)
static constexpr double	k2 (double tau, double zeta)
static constexpr double	fw_gain ()

Protected Attributes
u64	kp
u64	ki

Member Data Documentation

SCALE

constexpr unsigned satcat5::ptp::CoeffPI::SCALE = 60

staticconstexpr

Fixed-point scaling of each coefficient by 2^-N.

Optimized for time constants circa 1-3600 seconds.

Definition at line 239 of file ptp_filters.h.

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The documentation for this struct was generated from the following file:

• ptp_filters.h