FeedForward Class Reference

#include <feedforward.h>

Classes
struct	ff_config_t

Public Member Functions
	FeedForward (ff_config_t &cfg)
double	calculate (double v, double a, double pid_ref=0.0)
	Perform the feedforward calculation.

Detailed Description

FeedForward

Stores the feedfoward constants, and allows for quick computation. Feedfoward should be used in systems that require smooth precise movements and have high inertia, such as drivetrains and lifts.

This is best used alongside a PID loop, with the form: output = pid.get() + feedforward.calculate(v, a);

In this case, the feedforward does the majority of the heavy lifting, and the pid loop only corrects for inconsistencies

For information about tuning feedforward, I reccommend looking at this post: https://www.chiefdelphi.com/t/paper-frc-drivetrain-characterization/160915 (yes I know it's for FRC but trust me, it's useful)

Author

Ryan McGee

Date

6/13/2022

Constructor & Destructor Documentation

FeedForward()

FeedForward::FeedForward ( ff_config_t & cfg )

inline

Creates a FeedForward object.

Parameters

cfg	Configuration Struct for tuning

Member Function Documentation

calculate()

double FeedForward::calculate ( double v, double a, double pid_ref = 0.0 )

inline

Perform the feedforward calculation.

This calculation is the equation: F = kG + kS*sgn(v) + kV*v + kA*a

Parameters

v	Requested velocity of system
a	Requested acceleration of system

Returns

A feedforward that should closely represent the system if tuned correctly

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

• feedforward.h